The true origin of "Indian Summer" is likely a hybrid of these histories. It was a practical marker for the harvest, an observation of atmospheric haze, and perhaps, a reflection of the complicated racial dynamics of the colonial era.
The earliest known written record of the phrase appears in a letter from 1778 (written by a French-American soldier named St. John de Crèvecœur). He wrote: "Then a severe frost succeeds... which is often followed by a short interval of smoke and mildness, called the Indian Summer." He explicitly linked it to Native American hunting seasons. origin of term indian summer
Crèvecoeur’s account suggests the term was already in colloquial use among settlers and frontiersmen, implying an oral tradition that predates his writing by perhaps several decades. This situates the coining of the term firmly in the colonial and post-colonial Northeast. The true origin of "Indian Summer" is likely