This paper examines correspondence education as an alternative educational pathway in early 20th-century America. Using newly digitized records from the International Correspondence Schools—the largest such institution, with over 4 million students by 1940—linked to census data, I show that enrollment increased the likelihood of skilled employment by 6-10pp within 3-10 years, particularly among younger students who used it as a substitute for high school. I develop a general equilibrium Roy-style model where individuals sort into educational options by ability. Consistent with the model, correspondence education facilitated skill acquisition for lower-ability individuals and improved selection into high school, amplifying its returns.