Head Start is a federal program that has provided comprehensive early childhood development services to low-income children and their families since 1965. The comprehensive nature of the program includes educational, health, nutritional, and social services. These services are intended to prepare children to enter kindergarten and to improve the conditions necessary for their success in later school and life. Most children served in Head Start programs are three- and four-year olds, but in 1994 legislation expanded Head Start to include an Early Head Start program, which serves children from birth to three years of age. The term Head Start in this report typically refers to both of these programs. This report provides background and funding information throughout the years since its enactment for the Head Start program.