Born in Perryville, Missouri to German immigrants, Kiefner attended the public school system. He engaged in the retail lumber business and also in road construction. Kiefner served as mayor of Perryville from 1900 to 1902 and was a member of the State house of representatives from 1902 to 1908. He served as delegate to the Republican National Convention in 1912 and served on the staff of Governor Arthur M. Hyde from 1920 to 1924.