The two major issues being debated in the United States during Thoreau's life were slavery and the Mexican-American War. Both issues play a prominent part in Thoreau's essay. By the late 1840s, slavery had driven a wedge in American society, with a growing number of Northerners expressing anti-slavery sentiments. In the 1850s, the country became even more polarized, and the introduction of slavery-friendly laws such as the Fugitive Slave Law, prompted many abolitionists to protest the government's actions via various forms of civil disobedience. (Slavery was only to come to an end a generation later when the abolitionist North would win the Civil War [1861-1865], Abraham Lincoln's Emancipation Proclamation would free all slaves in Confederate territory. Eventually, the 13th Amendment would ban slavery everywhere.) In addition to this domestic conflict, the Mexican-American War (1846-1848) proved to be a point of much contention. Precipitated by boundary disputes between the United States and Mexico, the war was ultimately fought in order to expand American territory—many Americans felt it was their "Manifest Destiny" to seize all the land they could—and as a result the United States gained much of the present American Southwest, including California, Nevada, and Utah. Thoreau and other opponents of the war argued that the campaign constituted an unnecessary act of aggression and that it was pursued on the basis of arrogance rather than any philosophically justifiable reasons.

Civil Disobedience enjoyed widespread influence, both in the United States and abroad. Most famously, the work inspired Russia's Leo Tolstoy and India's Mahatma Gandhi. Later, it lent force to the American Civil Rights Movement. Thoreau died of complications from tuberculosis, which he contracted in 1835, in 1862.