Born in Pennsylvania in 1858, Elmer C. Patterson moved to Iowa as a boy. After graduating from Lenox College in Hopkinton, Iowa, in 1882, he spent eight years as a school-teacher and principal in Iowa. He then went to South Dakota, where he owned and edited the Pierre Daily Capital.
Admitted to the bar in 1892, Patterson practiced law in Huron, S.D. where he was a justice of the peace and city treasurer. He later practiced in Redwood Falls, Minn., and Marshall, Minn.; he was the judge of probate in Marshall from 1903 to 1907.
Patterson arrived in Minneapolis and opened a law practice in 1909. Four years later he became the first dean of Minnesota College of Law, a position he held for five years. Patterson published A Brief Treatise on the Law of Mortgages in 1915. Later, he served as dean of Minneapolis College of Law.