Lamar Jeffers attended public schools and the Alabama Presbyterian College in Anniston. He served 1904-1914 in the Alabama National Guard. Then he took in January 1917 to a position as a civil servant ( clerk ) at the District Court of Calhoun County. He held this post until May 1917, when he joined the U.S. Army where he served in the 82nd Division in France. During this time, the Distinguished Service Cross he was awarded. Furthermore, he was promoted to major in the infantry.
Jeffers was elected to the 67th Congress, there to fill the vacancy that was created by the death of Mr Fred L. Blackmon. He was re- elected to the 68th U.S. Congress and the five succeeding U.S. Congresses. In 1934 his candidacy for the 74th U.S. Congress, he suffered a defeat. Jeffers worked in the U.S. House of Representatives on June 7, 1921 to January 3, 1935. During this time, he had presided over the Committee on Civil Service ( 72nd and 73rd U.S. Congress ). He then returned to Daytona Beach, where he died in 1983. He was buried at Arlington National Cemetery.