In 1997, Mister Rogers' Neighborhood surpassed Captain Kangaroo as the longest-running children's television series.
Captain Kangaroo, hosted by Bob Keeshan, aired on CBS from 1955 to 1984 and was the longest-running children's program on a commercial network. Mister Rogers' Neighborhood, which began nationally in 1968, overtook it in May 1997 when measured by the length of its television run.
The comparison is sometimes misunderstood because Captain Kangaroo had far more episodes—6,090 in its original run—while Mister Rogers' Neighborhood had a much smaller production schedule. The record concerned longevity, not episode count or total hours broadcast.
Mister Rogers' Neighborhood held the longevity distinction until June 2003, when Sesame Street surpassed it. The series itself continued through 2001, with PBS stations later carrying reruns.