Monroe Mark Sweetland was born in Salem, Oregon, in 1910. His family moved to Michigan in about 1915, and he spent the bulk of his childhood there. He began his involvement with the Democratic Party when he was just 10 years old by clandestinely organizing a party meeting. He entered Wittenberg University in Ohio at age 16, then attended Cornell University and Syracuse Law School in New York. He met Lillie Megrath while attending Syracuse Law School and they were married in 1933. He returned to Oregon in 1935 and subsequently worked with the Commonwealth Federation, promoted progressive politics, and was instrumental in the rise of the Democratic Party to political power in the state. He also owned several newspapers in Oregon, including the Molalla Pioneer, the Newport News, and the Milwaukie Review. He represented Clackamas County in the Oregon House of Representatives 1953, and served in the Oregon Senate from 1955 to 1962. After leaving the Legislature, he moved to California and lobbied for the National Educaton Association. After retiring from politics, he began a business selling dried floral arrangements, called Western Wilderness Products. He returned to Oregon after Lillie died in 1985, and he ran unsuccessfully for the Oregon Senate again in 1994. He died in 2006.

Lillie "Lil" Megrath Sweetland was born in New Jersey in 1912. She attended Smith College in Massachusetts and met Monroe Sweetland while living in New York. They were married in 1931. She died in 1985.