Albert Raddin Sweetser established the University of Oregon Herbarium and for twenty-nine years was a much-loved teacher of botany. He was an early Oregon conservationist and author of many popular natural history articles. Early in his tenure at Oregon, he was appointed State Biologist.

Sweetser was born in Mendon, Massachusetts, on July 15, 1861, the son of a Methodist minister. He attended Wesleyan University in Connecticut, where he received his bachelor’s degree in 1884 and his master’s degree in 1887. He married Carrie Knowles Phinney in 1888. In 1893, Sweetser entered Harvard Graduate School, where he was a teaching assistant in botany; he also taught at Radcliffe College.

Albert and Carrie Sweetser moved to Oregon in 1897 when he accepted a teaching position at Pacific University in Forest Grove. In 1902, he joined the faculty at the University of Oregon as professor of botany and became department head seven years later. He founded the University of Oregon Herbarium in 1903.

Sweetser's earliest pressed plant acquisitions were the large personal collections of Oregon pioneers Thomas Jefferson Howell (1842-1912) and William Conklin Cusick (1842-1922); each collection contained approximately 10,000 sheets. At the time, according to David Wagner, the herbarium "was considered the largest and finest herbarium at any public institution in the northwest."

During his tenure, Sweetser organized many student field trips and four summer school cruises to Alaska. His best-known student was Lilla Leach. Sweetser retired in 1931, the year he also received an honorary doctorate from the university. He died in Eugene on September 12, 1940, and is buried in Massachusetts.