This website is really useful! https://www.state.gov/j/drl/hr/
I believe it would be land and Gold.
During the earliest era of settlement, the colony promised settlers some amount of free lands if they're willing to move into a certain area.
Gold at that time was pretty easy to find on those land, so many of the settlers were really interested to came.
The US lost more soldiers than most European nations involved in the war.
Im not sure but I tried
