Owned-and-operated television stations in the United States

In the United States, owned-and-operated television stations (frequently abbreviated as O&Os) constitute only a portion of their parent television networks' station bodies, due to ownership limits imposed by the Federal Communications Commission (FCC). Currently, the total number of television stations owned by any company (including a television network) can only reach a maximum of 39% of the country; in the past, the ownership limit was much lower, and was determined by a specific number of television stations rather than basing the limits on total market coverage.

At the dawn of the American television industry, each company was only allowed to own a total of five television stations around the country. As such, when the networks launched their television operations, they found it more advantageous to put their five owned-and-operated stations in large media markets that had more households (and therefore, denser populations) on the belief that it would result in higher revenue. In other markets, they opted to run their programming on stations through contractual arrangements, making them affiliates instead.

The five-station limit posed a problem for the DuMont Television Network, the first attempt at a "fourth" television network. Paramount Pictures, which had owned KTLA (channel 5) in Los Angeles and WBKB (channel 4, now WBBM-TV on channel 2) in Chicago, owned a share of the network. However, the FCC declared that Paramount controlled DuMont and thus forbade the network and the studio from acquiring any more stations. This was one of the factors that led to DuMont shutting down in August 1956.

For much of the era from 1958 to 1986, the major network-owned stations were distributed as follows: ABC, CBS and NBC each owned stations in the top three markets (New York City, Los Angeles and Chicago). Between 1958 and 1965, fourth-ranked Philadelphia housed CBS-owned WCAU-TV (channel 10) and NBC-owned WRCV-TV (channel 3, now KYW-TV), a station which NBC had acquired two years earlier through a trade with Westinghouse Broadcasting in return for NBC's television and radio stations in Cleveland. The FCC reversed the trade in 1965 and NBC regained control of the Cleveland television station, which is today known as WKYC. Each network owned stations in other markets where the other networks did not: in addition to Cleveland, these were ABC's KGO-TV (channel 7) in San Francisco and WXYZ-TV (channel 7) in Detroit, NBC's WRC-TV (channel 4) in Washington, D.C., and CBS' KMOX-TV (channel 4, now KMOV) in St. Louis.

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