The American Civil War (1861-1867) was fought between the United States of America in the North, and the breakaway Republic of The Confederate States of America, also known as the Confederacy. The war began over the issue of the state's rights to slavery, and starting in 1860 after Abraham Lincoln clinched the election, twelve slave states seceded from the Union. Prior to 1862, it seemed as if the Confederacy would be unable to force a truce between the two nations. After General Lee was made aware of the loss of a copy of his Special Order 191, however, the Confederacy was able to achieve a string of close victories at Antietam and South Mountain. Lincoln's Emancipation Proclamation after the Battle of Gettysburg in June 1863, which ended in a stalemate, promised freedom to the slaves of the south, but France's recognition of the C.S.A. and subsequent naval assistance meant that the Union blockade was over, and the Union was forced into negotiations.
While negotiations remained inconclusive between October 1863 and May of 1864, fighting still persisted in the West. After losing support from the Union, and fearing a Confederate invasion, California and Oregon called on Mexico for aid. Benito Juarez's republic provided enough military presence along the Rio Grande to turn the Confederacy's focus away from the west, allowing the California militia to secure land around El Paso. When this news reached Jefferson Davis in Richmond, he promised more fighting with the north. William "Tecumseh" Sherman was unable to hold the Mississippi, and the cities of New Orleans and Vicksburg were retaken by Confederate troops in 1865. The development of trench warfare in Richmond and Petersburg brought the war to a halt, and soon the two opposing forces were in a stalemate. A truce was reached two years later in the spring of 1867, and Lincoln retracted his Emancipation Proclamation in return for a ceasefire.
These events had an enormous effect on the North American continent, and between 1867 and 1945, the region saw regular secessionary movements, including the secessions of Texas and Florida from the Confederacy, and the bloodless secession of California, Oregon, and the western territories.
By the end of the American Civil War, which was also known as the War of Northern Aggression in the South, and the Union-Confederate War by the rest of the world, the only regions relatively untouched by hostilities were New England and the West Coast states of California and Oregon. New England resented both the South and Washington for their losses in the war. Old talk of the Hartford Convention of 1815 questioned the strength of the Federal Govenrment, and many in the far north began to doubt Lincoln's ability to maintain the Union. Vice President Andrew Johnson, who's home state of Tennessee was now part of the Confederacy, and war hero General Ulysses S. Grant failed to gain enough votes in the Presidential election of 1868, and Horatio Seymour of the American Union party won. Seymour's term was marked by the sale of Kansas and Missouri to the Confederacy.
In the Confederacy itself, General Robert E. Lee was elected President in 1868 as well, and signed the treaty expanding slavery north into Kansas. Lee, however, was personally opposed to the institution of slavery, and several former Confederate Generals were well aware of his leanings. Nathan Bedford Forrest, a C.S.A. General, founded the Pro-Slavery Party in 1869 and took the Confederate House the next year. Forrest was well known for his aggressive tendencies against black northerners in the war, and personally oversaw the later years of the Andersonville Prison, where Union prisoners of war were still being kept by 1871. In 1873, after a close election between Lee and Forrest which saw Lee retain his office, Andersonville was closed and what few Union soldiers were left were returned to the North.
After hearing of how these men were treated, U.S. President Seymour threatened sanctions against the South. Fearing another war and with growing strain over the state economies due to a lack of rail connection to the East coast, the state assemblies of California and Oregon negotiated a declaration of independence with the Union. In 1875, the Republic of California declared its independence, and the U.S. sceded control of Nevada, Utah, Colorado, Arizona and New Mexico to the new Republic. This also had a secondary effect, as anxious calls by Southerners to annex New Mexico and Arizona into the C.S.A. were halted immediately by Mexico's recognition of the new Bear Flag Republic, and they still feared a war with Mexico. Monterey was established as the new Capital of the Republic of California, and the new country profitted greatly from the discoveries of silver and gold in the Sierra Nevada. They also profitted off of an arms industry that kept Mexico in control of its southern border regions, and even aided the nation in the annexation of Guatemala of 1885, after a Guatemalan extremist assassinated the Mexican Presidente.
The South wasn't free of secessionist movements either. After Lee's untimely death in 1874, his Vice President, Stonewall Jackson, enacted a system of tax breaks for slave-owning families. This expanded the slave trade with Africa ten-fold, but also resulted in slave rebellions in Alabama and Mississippi. Texan and Floridan volunteers, who joined expecting another war with the North, were now fighting guerrilla slaves throughout the forested south. Nearly 10,000 soldiers from these states had died by 1879, and neither state was pleased with the government. Many Texans, in fact, were angry at the south for not securing territory to the west, much of which was originally part of the Texan annexation. They also held some disdain for "Dixiecrats" who focused more on the original secessionist states than on others, like Texas and Virginia.
A series of rebellions throughout the state, as well as a continuing Native American civil war in Oklahoma that often crossed over into Texas, brought the state militia to declare independence from the Confederacy. Confederate armies were moved into Texas to deal with these secessionists, but the militia was nowhere to be found. Led by Francis Lubbock, the Texan Revolutionary Movement had fled into Oklahoma, where it began uniting the various Native tribes against the South. When support was strong enough, the armies poured into Texas in late 1880. A series of bloody battles resulted in a stalemate near the Mississippi, and Lubbock's army threatened to invade New Orleans and cut off trade with the North, which was helping to fund the reconstruction of most of the southwest Confederacy. Californian President Romualdo Pacheco stepped in, and negotiated terms between Jackson and Lubbock. Jackson agreed to grant Texas its independence, but only if it would too take the Oklahoma territories as well. Lubbock quickly agreed to these terms and welcomed the Indian nations in as Texans. Additionally, Texas was recognized by California, preventing Mexico from attempting to take back lost territories.