Spain's hold on Florida was tenuous in the years after American independence, and numerous boundary disputes developed with the United States. In 1819, after years of negotiations, Secretary of State John Quincy Adams achieved a diplomatic coup with the signing of the Florida Purchase Treaty, which officially put Florida into U.S. hands at no cost beyond the U.S. assumption of some $5 million of claims by U.S. citizens against Spain.
December 2, 1823
It stated that further efforts by European nations to colonize land or interfere with states in North or South America would be viewed as acts of aggression, requiring U.S. intervention
Indian Removal Act
May 28, 1830
a congressional act that authorized the removal of native Americans who lived east of the Mississippi river
Texas War for Independence
October 2, 1835 - April 21, 1836
Long-running political and cultural clashes between the Mexican government and the settlers in Texas were exacerbated after conservative forces took control and the Siete Leyes of 1835 were approved. It displaced the federal Constitution of 1824 with the 1835 Constitution of Mexico, thereby ending the federal system and establishing a provisional centralized government in its place.
The Oregon Trail is a 2,000-mile historic east-west-north-south large wheeled wagon route and emigrant trail that connected the Missouri River to valleys in Oregon.
Trail of Tears
1838 - 1839
an 800 mile forced march made by the Cherokee from Georgia to Indian Territory
In 1845, the United States of America annexed the Republic of Texas and admitted it to the Union as the 28th state
April 25, 1846 - February 2, 1848
The Mexican–American War, also known as the Mexican War or the U.S.–Mexican War, was an armed conflict between the United States of America and Mexico from 1846 to 1848 in the wake of the 1845 U.S.
June 15, 1846
The treaty brought an end to the Oregon boundary dispute by settling competing American and British claims to the Oregon Country, which had been jointly occupied by both Britain and the U.S. since the Treaty of 1818.
California Gold Rush
January 24, 1848
when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The first to hear confirmed information of the Gold Rush were the people in Oregon, the Sandwich Islands, and Latin America, who were the first to start flocking to the state in late 1848
December 30, 1853
a purchase from Mexico consisting of the land of Arizona and New Mexico
January 29, 1861
In the Louisiana Purchase of 1803, the United States (US) acquired all of the French claims west of the Mississippi River; the area of Kansas was unorganized territory.
April 12, 1861 - May 8, 1865
a civil war fought from 1861 to 1865 between the United States and several Southern slave states that had declared their secession and formed the Confederate States of America
May 20, 1862
Many United States federal laws that gave an applicant ownership of land, typically called a "homestead", at little or no cost.
1863 - 1869
The First Transcontinental Railroad was a railroad line built in the United States of America between 1863 and 1869 by the Central Pacific Railroad of California and the Union Pacific Railroad that connected its statutory Eastern terminus at Council Bluffs, Iowa/Omaha, Nebraska with the Pacific Ocean at Oakland, California on the eastern shore of San Francisco Bay opposite San Francisco. By linking with the existing railway network of the Eastern United States, the road thus connected the Atlantic and Pacific coasts of the United States by rail for the first time
Sand Creek Massacre
November 29, 1864
The Sand Creek Massacre was an atrocity in the Indian Wars of the United States that occurred on November 29, 1864, when a 700-man force of Colorado Territory militia attacked and destroyed a village of friendly Cheyenne and Arapaho encamped in southeastern Colorado Territory, killing and mutilating an estimated 70–163 Indians, about two-thirds of whom were women and children.
1867 - 1871
The Chisholm Trail was a trail used in the late 19th century to drive cattle overland from ranches in Texas to Kansas railheads.
Battle of Little Big Horn
June 25, 1876 - June 26, 1876
Battle Between the U.S. Army led by lieutenant Colonel George Armstrong Custer and Sioux forces led by Chief Sitting Bull
Oklahoma Land Rush
April 22, 1889
The Oklahoma Land Rush of 1889 was the first land run into the Unassigned Lands and included all or part of the 2005 modern day Canadian, Cleveland, Kingfisher, Logan, Oklahoma, and Payne counties of the U.S. state of Oklahoma.