His father was a teacher who encouraged his son to read, and Rex had read the entire Bible twice by the time he was 4 years old. At the age of 13 he was the state spelling-bee champion. He served two years in the U.S. Navy (as a yeoman on President Teddy Roosevelt's official yacht) and then spent about four years working at about thirty different jobs (in six states), including cigar store clerk, while he sold poems, stories, and articles to various magazines.
It was not his writing but his invention of a school banking system in about 1916 that gave him enough money to travel in Europe extensively. (About 400 U.S. schools adopted his system for keeping track of the money school children saved in accounts at school, and he was paid royalties.) In Paris in 1929 he wrote his first book, How Like a God. After writing three more successful novels, he returned to the U.S. and began writing detective stories. The first one was Fer-de-Lance, which introduced Nero Wolfe and his side-kick Archie Goodwin. That novel was first published as a serial in The Saturday Evening Post and then as a book in 1934.