1776 to 1890 –– innumerable 'Indian wars' 
 
The western frontier was pushed through the territories of one
Indian confederation after another, all the way to the Pacific. An
early and definitive example is George Washington's post-revolutionary
conquest of the Ohio Valley, where the Washington Family held deeds to
immense tracts of prime real estate never actually ceded by the
Indians. The lore that George was a "surveyor" is a populist
distortion; he was no blue collar grunt, laying out property lines to
earn a living. He was in fact the most ambitious of an elite family of
'land speculators' -- the colonial equivalent of venture capitalists --
and his toils were in the service of his own family fortune. Already
one of the richest people in post-revolutionary America, he was
determined to get even richer through the sale of his Ohio holdings,
and wasn't about to be stopped by 'two-legged vermin' like the Shawnees
and Miamis. To this end, he abused his dominance of the early federal
government, arranging for Revolutionary War veterans (a battle-hardened
militia) to be compensated with "land warrants" deep in Ohio's
wilderness, far beyond his own holdings. He also encouraged the
issuance of large bounties, equivalent to several months' income, for
Indian scalps along the upper Ohio River. These were essentially open
murder contracts that targeted ALL Indians, regardless of age, gender,
or tribal affiliation. By this means, genocide was openly subsidized
for decades wherever intact Indian cultures presented an obstacle to
"progress." Primitive as media was, its role in all this was crude but
sufficient: posting the bounties while inflaming the settlers' hatred
with tales of Indian atrocities, real and imagined. In the Ohio
Territory, these tactics rapidly progressed to open war, orchestrated
by Washington against Tecumseh's Shawnee Confederation, and then to the
total extermination and westward displacement of the Ohio tribes (2). 

2) Churchill, Ward. A Little Matter of Genocide: Holocaust and Denial
in the Americas, 1492 to the Present. (San Francisco: City Lights
Books, 1997) pp. 209 - 214