In May 1835, Austin's colonists learned that Mexico's tolerance for the evasions of slaveowners was drawing to a close, with its proposal of new abolition legislation. Alarmed, and with Austin imprisoned in Mexico for pushing for independence, colonists turned against the Mexican government, calling it "oppressive" and a "plundering, robbing, autocratical government" without regard for the security of "life, liberty or property." Resisting the impact a changed slavery policy would have on economic growth, and fearing rumors of Mexico's plan to free the slaves and turn them loose upon the colonists, shortly after Austin returned from Mexico, he and his colonists took up arms against the Mexican government. Austin later gained U.S. Government support for his revolution when he wrote to Senator Lewis F. Linn and pleaded that Santa Anna planned to "exterminate" all of the colonists and fill Texas "with Indians and negroes slaves."