Which of the following is NOT considered a factor toward the end of the frontier image?

By the end of the nineteenth century, the West was effectively settled. Railroads stretched across all parts of the region, from the Great Northern, which ran along the Canadian border, to the Southern Pacific that ran across Texas and the Arizona and New Mexico territories to link New Orleans and Los Angeles. The influx of homesteaders, ranchers, and miners swelled the census rolls and led to the admission of Nevada (1864), Colorado (1876), South Dakota, North Dakota, Montana, Washington (all four in 1889), and Idaho and Wyoming (1890) to the Union. New towns and cities created by the cattle or mining boom, such as Abilene, Denver, and San Francisco, dotted the trans‐Mississippi West.

Explanation:

The Oklahoma Land Rush. Under President Andrew Jackson, Native American tribes from the Southeast had been resettled in what became Oklahoma. Long considered remote and unproductive, the land became increasingly valuable and, by the 1880s, the federal government was under pressure to open it to non‐natives for settlement. Congress responded by putting two million acres of the Indian Territory into the public domain. At noon on April 22, 1889, more than 50,000 men, women, and children (popularly known as the Boomers) on horseback, in wagons, and even on bicycles stampeded into what is now central Oklahoma to stake out their claims. Within a few hectic hours, all the available land was settled, with the choicest acreage actually going to the Sooners, those who had crossed the line before the official beginning of the land rush. An additional six million acres in the Oklahoma Panhandle called the Cherokee Strip was opened for settlers in 1893

the compromise of 1850 was a package of five separate bills passed by the united states congress in september 1850, which defused a four-year political confrontation between slave and free states on the status of territories acquired during the mexican–american war