My family also had the Ontario-Back to Niagara NY-MI trajectory in 1797-1830 time frame, so I suggest you investigate the Ingersoll land settlement and its defeat by a change in British policy. Settlers frum the US were invited to take up land on favorable terms by Mr. Ingersoll, but the land titles were not approved and many of the settlers returned to NY, acquiring land in the Holland Purchase area and then went to Michigan when land there was opened to homesteading. Look for your Howell and Vroman ancestors in the families attracted from western CT, and Dutchess County New York areas.

Not promising anything, but the similarities are there.

Earle Cummings