Head Start is the largest public pre-school program in the US, but it provides many additional services to families. This paper uses a discontinuity in grant writing assistance in the first year of the Head Start program to identify impacts on the work and welfare usage of mothers. Using restricted Decennial Census and administrative AFDC data I find that Head Start decreases employment rates and hours worked per week for single mothers. I also find a suggestive increase in welfare receipt for single mothers which is confirmed by an increase in the share of administrative welfare case-files that are single mother households. For all mothers combined there are no significant changes in work or welfare use. I also estimate long-run impacts, 10 years after a woman's child was eligible for Head Start. I find large and persistent declines in work for both non-white mothers and single mothers, accompanied by an increase in public assistance income and return to school. I argue that this is consistent with the 1960's era Head Start program's focus on encouraging quality parenting, parent participation and helping families access all benefits for which they were eligible.