Harper was born on Aug. 22, 1939, in Suffren, New York, and was raised in New Jersey. She made her Broadway debut in 1956 as a dancer in Li’l Abner.
She married actor Dick Schaal in 1964, telling PEOPLE in 1975: “He was my mentor. He totally brought me into acting. He’s read me lines for years and been nothing but supportive.” (They later divorced in 1978.)
Harper debuted as the kooky neighbor from New York on The Mary Tyler Moore Show in 1970.
Harper took home the Emmy for best supporting actress after the show’s first season alongside costar Ed Asner, who won best supporting actor.
Harper would eventually win four Emmy Awards and one Golden Globe for her role on The Mary Tyler Moore Show before getting her own spinoff.
Rhoda debuted on Sept. 9, 1974, to rave reviews and big ratings.
Mary Tyler Moore guest-starred in the final episode of the first season in March 1975.
Harper also starred in The Hogan Family, originally titled Valerie, opposite Jason Bateman.
Harper, whose film credits include, Freebie and the Bean (1974), The Last Married Couple in America (1980) and Blame It on Rio (1984), married her second husband Tony Cacciotti in 1987.
Harper reunited with Moore for the ABC telefilm Mary and Rhoda in 2000.
Harper was nominated for a Best Actress Tony Award nominee in 2010 for Looped. In 2013, she stepped down from the role of Tallulah Bankhead after being hospitalized.
In March 2013, Harper announced she had leptomeningeal carcinomatosis, a rare condition that occurs when cancer cells spread into the fluid-filled membrane surrounding the brain. She was diagnosed early with (and successfully treated for) lung cancer in 2009.
Harper competed on season 17 of Dancing with the Stars with pro partner Tristan MacManus.
One of Harper’s last red carpet appearances was a screening of My Mom And The Girl at The Hollywood Museum on November 8, 2017.