Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Frontier:

"

When the Republican Party came to power in 1860, it promoted a policy of a free land, notably the Homestead Act of 1862, coupled with railroad land grants that opened cheap (but not free) lands for settlers. In 1890, the frontier line had broken up; census maps defined the frontier line as a line beyond which the population was under 2 persons per square mile.[citation needed]