No single event or station introduced radio broadcasting to the entire United States. Instead, broadcasting activities evolved in many locations, slowly entering the public consciousness. By early 1922 there was enough organized activity for various publications to begin putting together national lists of stations that were providing broadcasts intended for the general public. However, because of the scattered nature of the activities, no single list at this time, including this one, was able to keep up with all the stations on the air.

The article below, which appears to date to around June, 1922, was prepared while U.S. broadcasting was going through an important transition. Initially there had been no restrictions on which radio stations could broadcast programs intended for the general public. But on December 1, 1921 the Bureau of Navigation issued a new regulation, which restricted non-government broadcasting to only those stations which held a Limited Commercial licence plus an authorization to use the Entertainment wavelength of 360 meters (833 kilohertz), and/or the Market and Weather wavelength of 485 meters (619 kilohertz). It took a few months for all the stations to fall in line with this new broadcast service regulation, which means that in the list below some stations from other licence categories are still included. However, these stations were now required to either get Limited Commercial licences or stop making broadcasts. (A review of how you can determine a station's licence classification from its callsign is included at the close of this list).

NOTE: A number of apparent callsign typos in the original article have been corrected. Following are the callsigns as they appear in the article below, followed, in parentheses, by the (incorrect) listing in the original article: KRE Berkeley, California (KFU), 2IA Jersey City, New Jersey (2A1), WOR Newark, New Jersey (WCR), 8UX Akron, Ohio (SUX), and WDZ Toledo, Ohio (WSZ). Also, other sources list WAI in Dayton, Ohio as "WA1".
 
The Home: 1923 Supplement, 1922, pages 65, 68:

The  Romance  of  the  Radiophone

In  Accomplishment  It  Eclipses  the  Wildest  Dreams  of  Fanciful  Fiction

By  LOUIS  JAY  HEATH

Assistant  Director  of  Educational  Work,  United  States  Public  Health  Service,  in  charge  of Radio Activities

ONCE more the dreams of the most daring weavers of scientific romance sink into the background before the accomplishments of present-day inventive genius. In 1887, when Edward Bellamy in "Looking Backward" predicted radio, his picture of radio receiving, which today is a common scene in thousands of American homes, seemed but the fanciful flashings of a vivid imagination. Yet in less than thirty-five years engineers delving into the mysteries of electrical transmission have passed beyond the limits of Bellamy's imagination and realized as wild a dream as the boldest maker of fiction ever wove.
    Three short years ago a man who told of picking from the air the musical notes of an opera or a concert given, hundreds of miles away would have been considered demented by a majority of the intelligent. Only here and there in laboratories and workshops the dreamers of radio broadcasting were pushing on. Then with the suddenness of a tropical storm radio burst upon the mind of the layman--of the man in the street.
    On June 1, 1922, according to the United States Department of Commerce, there were 301 licensed radio telephone broadcasting stations in the United States. These are scattered over forty-one states. At the same time the National Radio Chamber of Commerce reported that a nationwide survey had been made of' radio developments and that there were approximately one million five hundred thousand radio receiving sets already in use in American homes. So rapid is the development that figures become obsolete almost as soon as they are written.
national map

    Think of the possibilities! One million five hundred thousand American homes equipped with radio receiving sets! In that number of homes families, friends and neighbors are gathering about innocent looking boxes and are listening in on concerts, operas and lectures given in cities hundreds of miles distant. The latest news and the best music can be secured daily by merely tuning in on the radio without leaving the easy chair in your own living room. Nor is this all. It is possible that within the next year the Federal Government in Washington will be conducting the largest broadcasting service in the world. The details of a nationwide experimental service through high powered Government stations extending in a network across the continent are now being worked out. Already several departments are making extensive use of radio telephony. The United States Public Health Service of the Treasury Department has been operating a health information by radio service on a regular schedule since December, 1921. The Department of Agriculture has been using radio since November of last year to broadcast crop, market and weather reports; extensive plans are under way in the Bureau of Education in the Department of the Interior for a great educational service through Government stations; the Department of Labor is active, and other departments will soon be issuing educational news. The possibilities of radio as an educational medium seem boundless.
    So rapidly has the interest in radio transmission spread that the day is certainly not far distant when a radio receiving set will form a part, in fact a most important part, of the equipment of every American household. It is already possible for a man to deliver a message simultaneously in homes throughout hundreds of square miles of territory. The Public Health Information by Radio Service lectures of the United States Public Health Service, transmitted through NOF, the powerful Naval Aircraft Radio Laboratory station at Anacostia, D. C., have been heard simultaneously in Nova Scotia, Cuba and western Kansas. At some not far distant time, so great are the possibilities of radio, the President of the United States, when he has a message of general national interest to present, will not merely present it to Congress, but will speak into a broadcasting station that will send his words into the homes of the citizens in every state of the Union. Already voice broadcasting through NOF, on the banks of the Potomac, has been heard in southern California, and code messages from the same station have been picked up in Honolulu.
    No one can predict the future of radio or estimate what will be the value of its service to mankind. What will be the effect upon this little earth and its peoples when the voice of a man in Chicago, Washington, Paris, Berlin, Moscow or Tokio will be carried around the world? A new age is dawning--we stand watching that dawn and distances shrink, barriers of mountains and seas, barriers of language and illiteracy are being swept away. Who can say what radio will mean? Perhaps a United States of the World, united through the common medium that envelopes us all.
LOUIS  JAY  HEATH.      
  Wave
Length
WKH 360 Montgomery, Ala. Montgomery Light & Power Co.
WOK 360 Pine Bluff, Ark. Pine Bluff Co.
KRE 360 Berkeley, Cal. Maxwell Electric Co.
KFU 360 Gridley The Precision Shop
KGC 360 Hollywood Electric Lightning & Supply Co.
KLP   Los Altos Colin B. Kennedy Co.
KJS   Los Angeles Bible Institute of Los Angeles
KOG   Los Angeles Western Radio Electric Co.
KQL   Los Angeles Arno A. Kluge
KYJ   Los Angeles Leo J. Meyberg
KZC   Los Angeles Western Radio Electric Co.
DDV 360 Monterey Noble Electric Works
KLS   Oakland Warner Bros.
KZM   Oakland Hotel Oakland
KZY   Oakland Atlantic Pacific Radio Sup. Co.
KLB   Pasadena J. J. Dunn Co.
KGF   Pomona Pomona Fixture and Wiring Co.
KVQ   Sacramento J. C. Hobrecht (Sacramento Bee)
AGI   San Francisco Signal Corps Presidio
KDN   San Francisco Leo J. Meyberg Co.
KGB   San Francisco E. C. Lorden
KUO   San Francisco Examiner Printing Co.
KYY   San Francisco Radio Telephone Shop
KQW   San Jose Chas. D. Herrold
KJQ   Stockton C. O. Gould
KWG   Stockton Portable Wireless Telephone Co.
KJJ   Sunnyvale The Radio Shop
KIZ   Denver, Colo. Reynolds Radio Co.
WQB   Hartford, Conn. C. D. Tuska Co.
WCJ   New Haven A. C. Gilbert Co.
WDM   Washington, D. C. Church of the Covenant
WDW   Washington, D. C. Radio Constr. & Electric Co.
WJH   Washington, D. C. White & Boyer
WWX 1160-1980 Washington, D. C. P. O. Dept.
3YN 360 Washington, D. C. National Radio Inst.
4CD 200-375 Atlanta, Ga. Carter Electric Co.
KYW   Chicago, Ill. Westinghouse Elec. & Mfg. Co.
WBU   Chicago, Ill. City of Chicago
WOC 360-485 Rock Island, Ill. Karlowa Radio Co.
WLK 360 Indianapolis, Ind. Hamilton Mfg. Co.
WOH 360 Indianapolis, Ind. Hatfield Electric Co.
WOZ 360-485 Richmond, Ind. Palladium Printing Co.
WGF 360 Des Moines Register Tribune
9YA 360 Iowa City University of Iowa
9ARU 200 Louisville, Ky. Darrel A. Downard
WGI 360 Medford Hillside, Mass. American Research & Radio Corp.
WBZ 360 Springfield Westinghouse Elec. & Mfg. Co.
WWJ 360-485 Detroit, Mich. The Detroit News
WHW 485 East Lansing, Mich. Stuart Seeley
WLB 360 Minneapolis, Minn. University of Minnesota
WOS 485 Jefferson City, Mo. Missouri State Marketing Bureau
WOQ 360-485 Kansas City, Mo. Western Radio Co.
9YY 360 Lincoln, Neb. University of Nebraska
WOU 360-485 Omaha, Neb. Metropolitan Utilities District
WOV 360 Omaha, Neb. R. B. Howell
WNO 360 Jersey City, N. J. Jersey Journal
2IA 200 Jersey City, N. J. Jersey Review
WOR 360 Newark, N. J. L. Bamberger and Co.
WJZ 360 Newark, N. J. Westinghouse Elec. & Mfg. Co.
WDT 360 New York City, N. Y. Ship Owners Radio Service
WJX 360 New York City, N. Y. DeForest Rad. T. & T. Co.
WYCB 1450 New York City, N. Y. Amateur Radio Reserve
WHQ 360-485 Rochester, N. Y. Rochester Times Union
WGY 360 Schenectady, N. Y. General Electric Co.
WRL 360 Schenectady, N. Y. Union College
8UX 360 Akron, Ohio Radioart Store
WLW 360 Cincinnati, Ohio Crosley Mfg. Co.
WMH 360-485 Cincinnati, Ohio Precision Equip. Co.
WHK 360 Cleveland, Ohio Warren R. Cox
8BYV 200 Columbus, Ohio Electrical Specialty Co.
8YO 275 Columbus, Ohio Ohio State University
WFO 360-485 Dayton, Ohio Rike Kumler Co.
WAI 360 Dayton, Ohio U. S. Army
WL2 360 Fairfield, Ohio U. S. Army
WRK 360 Hamilton, Ohio Doron Bros. Electric Co.
WHU 360 Toledo, Ohio Wm. B. Duck Co.
WJK 360 Toledo, Ohio Service Radio Equip. Co.
WDZ 360-485 Toledo, Ohio Marshall-Gerken Co.
WGL 360 Philadelphia, Pa. Thos. F. J. Hewlett
KDKA 360 Pittsburgh, Pa. Westinghouse Elec. & Mfg. Co.
KQV 360 Pittsburgh, Pa. Doubleday Hill Elec. Co.
WRB 360 Pittsburgh, Pa. Newspaper Printing Co.
WRR 450 Dallas, Texas Police & Fire Signal Dept.
KFC 360 Seattle, Wash. Northern Elec. & Radio Co.
KHQ 360 Seattle, Wash. Louis Wasmer
KJR 360 Seattle, Wash. Vincent I. Kraft
WHA 360-485 Madison, Wis. University of Wisconsin

Callsigns and Licence Classifications: Most of the stations listed above which have callsigns starting with K or W (WRR, WGI, KYW, KZY, WQB, WJZ, KDKA etc.) held the Limited Commercial licences which, with the adoption of the December 1, 1921 broadcast service regulations, had become mandatory for private broadcasting stations. (Many of these stations had previously held licences in other classifications, especially Experimental and Amateur. Also, it was not uncommon for a station to hold more than one licence, and operate under different callsigns according to the licence classification it fell under at the time it was on the air).

But some stations in this list have callsigns that start with a number, which was the Radio Inspection District in which they were located, followed by two or three letters. Despite the similarity of their calls, these stations were actually divided among four different licence classifications, although what they did have in common was that, because of the December 1st regulations, they all were now required to get Limited Commercial licences if they wanted to continue to make broadcasts intended for the general public. A few stations in the above list had standard Amateur licences, which meant they normally transmitted on the congested wavelength of 200 meters (1500 kilohertz). The callsign rule for standard Amateur stations was that the letter following the district number could be anything except X, Y, or Z. The standard Amateur stations appearing in the above list are 4CD in Atlanta, Georgia, 9ARU in Louisville, Kentucky, 2IA in Jersey City, New Jersey, 8UX in Akron, Ohio, and 8BYV in Columbus, Ohio. The other three licence categories -- Experimental, Technical and Training School, and Special Amateur -- which had callsigns starting with district numbers were known collectively as the Special Land stations. These stations generally were allowed to transmit on the less congested wavelengths between 600 and 200 meters (500 to 1500 kilohertz). Experimental stations had callsigns with an X as the first letter following the district number. However, by the time this list appeared most Experimental stations making broadcasts had acquired broadcasting licences, so none appear in this list. Technical and Training School licences were most commonly issued to colleges and universities, and their callsigns had a Y immediately after the district number. Technical and Training School stations in this list include 3YN in Washington, D.C. (National Radio Insttute), 9YA Iowa City, Iowa (University of Iowa), 9YY, Lincoln, Nebraska (University of Nebraska), and 8YO, Columbus, Ohio (Ohio State University). Finally, Special Amateur licences allowed qualified amateurs to legally operate on the less congested wavelengths, and their calls had a Z after the district number. Like the Experimental stations, by the time this list appeared Special Amateur stations were no longer transmitting broadcast services.

A few U.S. Government stations are also listed. (Government stations were exempt from the private station requirement that broadcast stations have Limited Commercial licences.) Stations operated by the U.S. Navy were assigned calls starting with N, for example NOF in Anacostia, D.C., which is mentioned in the text of this article. The U.S. Army stations were supposed to use calls starting with WUA to WVZ and WXA to WZZ, for example WYCB in New York City. However, other Army stations at this time seem to have used whatever calls they wanted, including AGI in San Francisco, California, Fairfield, Ohio's WL2 and Dayton, Ohio's WAI (WA1 according to some other sources). Another government station included in this list is WWX, operated by the Post Office in Washington, D.C.

Additional Information: The various land station licence classifications are defined in the August 15, 1919 edition of Radio Communication Laws of the United States, beginning with regulation 51. For a detailed review of U.S. callsign practices, see United States Callsign Policies. For a comprehensive overview of the establishment of the Limited Commercial broadcast service and the current status of many of the stations listed above, see United States Pioneer Broadcast Service Stations. And for more information on radio station lists, see Early Radio Station Lists Issued by the U.S. Government.