This paper exploits a new source of variation in Head Start funding to identify the program's long-term effects. In 1965 the Office of Economic Opportunity (OEO) provided technical assistance to the 300 poorest counties in the U.S. to develop Head Start funding proposals, but did not provide similar assistance to other counties. We show that the result is a substantial difference in Head Start funding and participation rates in those counties just above and below OEO's poverty-rate cutoff for technical assistance, differences that seem to have persisted through at least the 1970’s. This discontinuity in Head Start funding and participation are associated with discontinuities in educational attainment.