Rising to the rank of lieutenant colonel by 1945, Chidsey served in a variety of administrative positions in Washington, D.C., and developed educational materials for the wartime Army.
After World War II, Chidsey briefly served as assistant dean of students of the University of Chicago, with supervision over undergraduate activities.
In 1946 a group of prominent Houstonians invited Chidsey to their city to discuss the establishment of a coeducational private school.
He was asked to spearhead efforts which led to the establishment of St. John's School, located in the River Oaks neighborhood of Houston.
Chidsey was also the author of several books, including historical works on Rustam, Odysseus, and Romulus; Heinz, a satire of service in World War II; and My Animal Friends, a book of poems about animals with lessons for people.