From 1922-29 Major Lohr worked in various capacities for the Army from 1922-29 including executive secretary of the Society of American Engineers and was the editor of its journal "The Military Engineer". In 1929 he resigned from the Army and was hired by Rufus C. Dawes, brother of former vice-president, Charles Dawes, as general manager of Chicago's Century of Progress world's fair. In his role he was primarily responsible for the coordination of construction, promotion and financial organization. The Century of Progress exhibition was a rare example of a world's fair that not only repaid all its investors in full, but closed with a surplus.