Born in Milton, Pennsylvania, Follmer received an Artium Baccalaureus degree from Bucknell University in 1906 and a Bachelor of Laws from Harvard Law School in 1909.

He was the United States Attorney for the Middle District of Pennsylvania from 1935 to 1946.

He was confirmed by the United States Senate on July 31, 1946, and received his commission on August 7, 1946.

His service in the Eastern District and Western District terminated on June 1, 1955, due to reassignment by operation of law.

He served as Chief Judge of the Middle District in 1962.