Webster's Revised Unabridged Dictionary · 1913

Mackinaw blanket

Mackinaw blanket

[From Mackinac, the State of Michigan, where blankets and other stores were distributed to the Indians.]

1.
A thick blanket formerly in common use in the western part of the United States.
2.
a heavy woolen cloth heavily napped and felted, often with a plaid design.

Also: Mackinaw