The influential pamphlet written by Thomas Paine that motivated colonists to fight for independence was "Common Sense," published in January 1776. In this powerful work, Paine argued for the necessity and legitimacy of independence from British rule, advocating for republicanism and criticizing monarchy. His straightforward language and compelling arguments resonated with the colonists, effectively galvanizing public sentiment against British oppression. The pamphlet challenged the prevailing idea of loyalty to the crown and encouraged individuals to envision a new nation based on democratic principles and human rights, significantly influencing the course of the American Revolution.