Final answer:
Thoreau opposed the war because he believed in individual freedom and moral responsibility. He advocated for civil disobedience as a form of protest against unjust government actions like the Mexican-American War and slavery. Thoreau's passive resistance approach influenced many global freedom movements.
Step-by-step explanation:
Henry David Thoreau's opposition to the war, notably the Mexican-American War, is rooted in his belief in individual freedom and moral responsibility. Thoreau was a staunch advocate for civil disobedience, a form of protest where individuals refuse to follow laws they consider unjust. In "On the Duty of Civil Disobedience," Thoreau eloquently argues against governmental actions that violate his conscience, such as the government's support for slavery and the unjust war with Mexico. By refusing to pay his poll tax, Thoreau protested what he deemed immoral government actions. His act of not paying was not merely a stance against specific policies but a broader statement about the individual's duty to live by their ethical beliefs, even if that means going against societal norms and legal obligations.
In Walden; or Life in the Woods, Thoreau extends his discussion of freedom, highlighting the importance of living simply and in harmony with nature as a form of personal liberation from societal expectations. He emphasizes the power of individualism and the role nature plays in achieving a transcendental state of mind. Thoreau's commitment to these ideals is exemplified by his own life choices, such as his residency at Walden Pond, where he sought to live according to his principles and minimize reliance on societal structures.
Thoreau's philosophies, outlined in his essays and practiced in his life, hold that a just man in an unjust society must take a moral stand, sometimes even ending up behind bars to make a statement against an oppressive government. His peaceful approach to protesting injustice—what he called passive resistance—has had a significant influence on global movements seeking freedom, inspiring leaders such as Gandhi and Martin Luther King Jr., and continues to be a powerful force in the struggle for civil rights and societal reform.