Polly v. Lasselle (Knox Co. Court Record #2490 [90-146-32] and #2890-2) was an 1820 Indiana Supreme Court case where abolitionists attempted to free a slave from her master. The case resulted in the court ordering all slaves held within Indiana to be freed.
Slavery had been a legal institution in the region of Indiana when it was controlled by France and Great Britain, and remained legal until 1787 when the Northwest Territory was organized by the United States of America. The Northwest Ordinance prohibited further expansion of slavery in the region, but allowed for the continuation of existing slave arrangements.
When the Indiana territory was established in 1800, many slaveholders immigrated to the territory bringing their slaves with them. The territory passed legislation that allowed for the slaves to be indentured within the territory. This law allowed slaveholders to continue in their ownership of slaves that were purchased outside of the state, even if the slaves came to reside in Indiana.
When Indiana was granted statehood in 1816, the constitution instituted a ban on slavery. This ban brought the previous laws that had permitted slavery into conflict, and the issues of whether preexisting slave arrangements were still legal was brought before the courts on several occasions. Each time the circuit courts had denied or approved the freedom of the slaves on an individual basis.
In 1819 two abolitionists, John Osborn and Amory Kinney, sought the aid of a Vincennes law office to test the legality of slave arrangements made prior to 1816. The two were Canadians who had immigrated to Indiana after the War of 1812. They believed that the constitutional ban on slavery extended to all slaves, including those held before 1816. The lawyers at the office, Colonel George McDonald and Moses Tabbs, also members of the anti-slavery party, began to prepare a test case to bring before the courts.