The annexation of Texas opened a new chapter in our history. It brought on the Mexican-American War. That brought a large addition to our territory. It was necessary to settle the question of slavery in the annexed territory and this opened the slavery question anew. Both of the old parties were after a while split asunder by the debate, and the question of slavery or no slavery in the Territories became the leading issue in our politics. In sixteen years from the annexation of Texas, this chain of causes had plunged the country into the most tremendous civil war in the history of the world. In just twenty years the war had ended in the entire abolition of slavery in the United States. Thus, the annexation of Texas brought about unforeseen results, and changed the history of the continent.

After the Missouri Compromise in 1820, it had been an accepted maxim in our politics that the slavery discussion should not be reopened. The antislavery people who persisted in agitating the question were thought unpatriotic. They were severely persecuted even by Northern people, who feared that their agitation of the subject might destroy the Union of the States.

But when the arrangement made by the Missouri Compromise was once disturbed by annexing Texas and other Mexican territory, the political struggle between the free and slave states began anew. In 1846, during the Mexican-American War, a bill was introduced in Congress looking to a peace with Mexico, to be made by a purchase of territory. Mr. Wilmot, of Pennsylvania, moved to add a proviso that slavery should never exist in the territory thus acquired. This was known as "the Wilmot Proviso." The proviso was finally rejected, but it opened the question of freedom or slavery in the new territory before the Mexican-American War was ended.

The first effect of the excitement was to render certain the defeat of the Democratic party in the election of 1848. A large number of Democrats and a smaller number of Whigs seceded from the old parties and formed the Free-Soil party, which desired to shut slavery out of the Territories. The Democrats nominated General Cass; the Whigs nominated General Zachary Taylor, the hero of Buena vista, for President. The Free-Soilers nominated ex-President Martin Van Buren. Taylor elected, a year and four months, President Taylor died, and was succeeded by Millard Fillmore, the Vice President.

But while the country was excited over the presidential election, an event took place in the newly annexed Territory of California that gave new violence to the slavery debate. Particles of gold were discovered in the Sacramento River in California in 1848. The California mines proved to be the richest in the world. A great rush of people to the new Territory set in. Ships loaded with passengers sailed around Cape Horn, and trains of ox-carts went across the plains, then occupied only by American Indians. In 1849 the people of California set up a State government without authority from Congress, and asked to be immediately admitted to the Union. As part of the new State was south of the Missouri Compromise line, and as its Constitution forbade slavery, the slave states were opposed to this addition to the number of free states.

Meantime the growing anti-slavery sentiment at the North made it harder to reclaim runaway slaves, who escaped in large number to the free states. The Southern States complained of this as a violation of the Constitution, which provided that all such fugitives should be sent back. The Northern States complained that the public traffic in slaves in the city of Washington was highly improper in the capital of a free country.

The veteran statesman Henry Clay had always been a skillful compromiser of difficulties. He now arranged and carried, with the help of Webster and others, the measures which have since been known as "The Compromise of 1850." By this compromise slavery was to be continued in the District of Columbia, but the buying and selling of slaves there was to be abolished. At the same time a new and severe law was made for the return of fugitive slaves, which was no longer left to the States, but entrusted to United States officers. California was admitted as a free State, and New Mexico organized as a Territory without slavery. The leading statesmen of the country imagined that these measures, which gave something to each side, would forever put to rest this dangerous question.

There was indeed a lull in the excitement. The little Free-Soil party, which had helped to defeat the Democrats in 1848, cast fewer votes in 1852 for its candidate, John P. Hale, than it had cast for Van Buren in 1848. The Whigs nominated General Winfield Scott, the conqueror of the city of Mexico, but divisions on the slavery question had broken the power of that party, and Franklin Pierce, of New Hampshire, the Democratic candidate, was elected by a large majority.

The Compromise of 1850 did not prove to be, what its promoters called it, "a finality"; that is, an end of the debate. The fugitive-slave law exasperated the Northern people. Every black person claimed under it excited the sympathy of the people and awakened opposition.

The anti-slavery sentiment at the North was quickened and diffused at this time by the publication of the novel entitled "Uncle Tom's Cabin." It excited sympathy for slaves, and it at once reached a circulation that has hardly an equal in the history of literature.

The South was equally dissatisfied. The violent censures of anti-slavery speakers and writers excited bitter feelings. It soon became evident also that about all of the territory remaining to be admitted into the Union would, in the nature of things, come in as free states. It was seen that this would put the slave states in the minority, and destroy what was called "the balance of power" between the two sections.

Attempts were therefore made to purchase the Island of Cuba, in order to make new States from it. But Spain refused to sell Cuba. The desire of our people for new territory had been greatly inflamed by their recent acquisitions, and threats were made to seize Cuba by force. Expeditions were secretly fitted out in the United States to promote insurrections in the island, but they came to nothing. Several attempts were made by "filibusters" to seize territory from the weak states in Central America. These were continued until 1860, when the chief filibuster, William Walker, was captured and executed by Central American authorities.