Appendix to : "How America Graduated from High School, 1910 to 1960", Construction of State-Level Secondary School Data

A new state-level series on secondary-school data demonstrates that graduation and enrollment rates increased greatly in the 1920s and 1930s in most regions. An 18-year old male in 1910 had just a 10% chance of having a high school diploma but by the mid-1930s the median 18-year old male was a high school graduate. This Appendix describes the procedures used to construct the state-level secondary school enrollment and graduation numbers contained in the NBER Working Paper `How America Graduated from High School: 1910 to 1960.'