The following was not a reason why the Plains Indians were so difficult to defeat in
the 1800s:

The Real Reason: Plain Natives were always on the move, sort of like nomads

What WASN'T the reason: Plains Natives had settlements and never migrated

Explanation:

Plains natives were difficult to defeat because they were always on the move, so the U.S. or Mexican Army couldn't catch up to them. While natives who weren't on the move and had established settlements, were situated in a single place which would allow europeans to raid and destroy their settlement.

so, the wrong reason for why the plains nations were so difficult to defeat would be to say they were a situated settlement and were never migratory or "on the move"

the alfred thayer mahan award for literary achievement is awarded each year by the navy league of the united states. the award is named for an american naval historian and theorist, rear admiral alfred thayer mahan, united states navy who, through his writing, provided stimulus and guidance to those who share in the defense of the nation. presented since 1957, "this award for literary achievement is awarded to a u.s. navy officer, u.s. marine corps officer, enlisted service member, or civilian who has made a notable literary contribution that has advanced the knowledge of the importance of sea power in the united states."[1]

b.lincoln had the victory he wanted for emancipation