Convergence: David Douglas, . . .

Jackphiladelphia,comingexpandinglondon,athe

Also by Jack Nisbet on Discovering Lewis & Clark®:

David Thompson, Lewis & Clark, Thomas Jefferson

Photos in the V above, top to bottom, left to right:
Alexander Mackenzie, William Bartram, David Hosack, William Jackson Hooker,
Meriwether Lewis, Alexander von Humboldt, William Clark, David Douglas.