How did slavery influence Henry David Thoreau’s opposition to the Mexican-American War?

Henry David Thoreau’s opposition to the Mexican-American War was fundamentally rooted in his stance as an abolitionist. He viewed the conflict as an imperialist effort by slave states to expand their power and territory, specifically by creating new slave states from lands acquired from Mexico.123

Because he believed the U.S. government was endorsing slavery through this war, Thoreau felt he could not morally support the state. In July 1846, he demonstrated this conviction by refusing to pay his poll tax, an act of protest that led to his brief imprisonment.321

Thoreau documented his philosophical opposition to these government actions in his influential essay, "Civil Disobedience," where he argued that individuals must prioritize their moral conscience over the laws of a government that perpetrates injustice. He famously asserted that if a law requires one to be the agent of injustice to another, one should break that law, effectively acting as a "counter friction" to stop the machine of the state.312