The Small Fry Club, also known as Movies for Small Fry, was one of the earliest TV series made for children. It aired until June 15, 1951 on the DuMont Television Network  
and was hosted by "Big Brother Bob Emery" (shown below).The Small Fry Club originally aired weekly, but soon expanded to five days a week. According to television historians, it was possibly the first television series to air five days per week. Before it was on TV, the show got its start on radio, in Boston, Massachusetts.

Big Brother Bob Emery (real name Clair Robert Emery)

Bob Emery (left) with quests Kukla, Fran and Ollie

What’s My Line? a panel game show which originally ran on the CBS Television
Network from 1950 until it’s cancellation in 1967. It is the longest-running game
show in the history of U.S. prime time television. It was hosted by John Charles
Daly with panelists Dorothy Kilgallen. Arlene Francis, and Bennett Cerf. 

The show won three Emmy Awards for “Best Quiz or Audience Participation Show”
in 1952, 1953 and a Golden Globe for Best TV show in 1962. After it was 
cancelled by CBS in 1967, it returned in syndication as a daily production
returned in syndication as a daily production which ran from 1968 until 1975.