The Massachusetts Emigrant Aid Company was founded in 1854 by Eli Thayer of Massachusetts to support anti-slavery settlement of the Kansas territory. Thayer and his partners believed that if enough "free-staters" established themself in Kansas, they would prevent state-sanctioned slavery by exercising their right to popular sovereignty. In 1855, the company reorganized and changed its named to the New England Emigrant Aid Company. One of the Kansas towns the company was responsible for founding is Lawrence, Kansas.