What events led to the closing of the west?

Massive influx of  influx of homesteaders, ranchers, and miners swelled

Explanation:

The West frontiers were initially opened in order to attract as many immigrants as possible to occupy the land that exist In United States.

By the end of the 18th century, the influx of  homesteaders, ranchers, and miners far surpassed the amount of land and job opportunities that's available in the Western Frontier.

So, the government decided to close it before the regions became overpopulated and people forced to do crimes because they couldn't find sources of income.

a is the final : )

"germany's geographic location was an advantage when it was on the offensive in the war because it was situated next to an extremely wide river, the rhine, which was difficult for the allies to cross."