Where can I watch The Bill Cosby Show in United States?

The Bill Cosby Show is an American situation comedy that aired for two seasons on NBC's Sunday night schedule from 1969 until 1971, under the sponsorship of Procter & Gamble. There were 52 episodes made in the series. It marked Bill Cosby's first solo foray in television, after his co-starring role with Robert Culp in I Spy. The series also marked the first time an African American starred in his or her own eponymous comedy series.