The American Broadcasting Company (ABC) first aired Saturday morning television shows for children on August 19, 1950. The network introduced two shows: Animal Clinic, which featured live animals, and the variety show, Acrobat Ranch, which had a circus theme. The latter show, hosted by Jack Stillwell ("Uncle Jim"), featured two young acrobats, Tumbling Tim and Flying Flo, and children competing in games and stunts.
The first children's entertainer to perform for television was Burr Tillstrom, who broadcast live from the New York World's Fair in 1939. The National Broadcasting Company (NBC) began the first regular television broadcasts in the United States the same year. Initially, the network offered just two hours of programming per week, which were to be received on RCA television sets.
Children's television evolved slowly during the early years. Network executives assumed that families would view programs on their (single) TV set together. Consequently, programming was geared to families while advertising targeted adults. Several children's shows emerged in the late 1940s and early 1950s including Bob Emery's The Small Fry Club, Burr Tillstrom's Kukla, Fran, and Ollie, and Robert E. "Buffalo Bob" Smith's The Howdy Doody Show. The Columbia Broadcasting System (CBS) began airing animated cartoons in 1955 under the title Mighty Mouse Playhouse.