US Census Bureau
U.s. Census Bureau: Age Data
This website has data available on age at the following levels: National, State, County, and other. Other statistical sections are "International Data," "Baby Boomer," "Older (55+) Population," and "Elderly (65+) Population."
Other
Kingwood Library: American Cultural History: 1960 1969
An historical record worth delving into to understand the true culture of the 60s. Covers art, architecture, literature, education, fashion, historic events, music, and other aspects of the era.