It is technically false that the Frontier ended when the open land was gone, since the open land was never "gone" just either taken up by private owners.
Crime can affect communities in many ways, but perhaps the greatest economic impact is that more security forces are needed, which costs lots of money.
The Louisiana Purchase: Jefferson's constitutional gamble. On October 20, 1803, the Senate ratified a treaty with France, promoted by President Thomas Jefferson, that doubled the size of the United States. ... The land involved in the 830,000 square mile treaty would eventually encompass 15 states.
John D. Rockefeller (1839-1937), founder of the Standard Oil Company, became one of the world's wealthiest men and a major philanthropist. Born into modest circumstances in upstate New York, he entered the then-fledgling oil business in 1863 by investing in a Cleveland, Ohio, refinery.
