Agent Six has provided a verifiable example from 1976.
The sarcastic interjection ‘in your (or my, her, his, etc.) dreams’ is familiar in everyday spoken English, but the earliest evidence our editors have found comes from a Usenet post in 1986. We suspect that it may have been used earlier […]
OED contributor Fred Shapiro has supplied an example from 1970.
The winter festival of Kwanzaa was initiated in 1966 by Maulana Karenga, an African-American activist and scholar, but the earliest example in the OED is from […]