Which preposition to use with powwow

with Occurrences 3%

I had had ample time since the powwow with Thayendanega to decide whether or no I would serve under General Herkimer, and, having come to a decision, it stood me in hand to do whatsoever lay before me without question.

in Occurrences 2%

At Kingston, while they were still one body and soul, and kept up their union with constant powwows in one another's rooms, but most often in Tug's, they were divided variously among the athletic teams, where each one felt that his own honor was Lakerim's.

Which preposition to use with  powwow