Adair was born in Clayton, Illinois, attending public high school, and Illinois College in Jacksonville, Illinois. He graduated from the University of Michigan Law School in 1911 with a Bachelor of Laws. He was admitted to the bar the same year and commenced practice in Muskogee, Oklahoma. He moved to Quincy, Illinois, in 1913 and continued the practice of law. He also engaged in agricultural pursuits and in the manufacture of medicine for livestock. He served as city attorney of Quincy from 1914 to 1916. He served as prosecuting attorney of Adams County, Illinois from 1916 to 1920 and from 1924 to 1928. He was in private practice in Adams County from 1920 to 1924. He served as member of the Illinois Senate from 1928 to 1932, from the 36th District.[1][2][3]