The sitcom starring Lucille Ball and Desi Arnaz ran on CBS from 1951 to 1957 and starred Ball as Lucy Ricardo, the luckless wife of bandleader Ricky (Arnaz). The two spent time with their neighbors and landlords Fred (William Frawley) and Ethel (Vivian Vance) as Lucy tried frequently to break into show business.
The couple's son Little Ricky was portrayed by five actors as he grew up in real-time, including two sets of twins. While "Lucy" is often credited with showing a pregnant woman for the first time, the distinction actually goes to "Mary Kay and Johnny," a sitcom that ran from 1947 to 1950. However, the network wouldn't allow the word "pregnant" to be used, so "Lucy" scripts always used the term "expecting."
"Much of its classic status can be attributed to the show's physical comedy, which Ball would spend hours perfecting," writers Ken Bloom and Frank Vlastnik wrote in the book "Sitcoms: The 101 Greatest TV Comedies of All Time."