Not sure about that. Both Indiana (1816) and Illinois (1818) abolished slavery by their constitutions. There may have been some slaves before Indiana became a state. And racism, while slowly dying, persists to this day.
Some individual southern sympathizers went to Kentucky to join up with the Confederates.
from Wikipedia:
Despite significant anti-war activity in the state and southern Indiana's ancestral ties to the Southern United States, it did not secede from the Union. During the course of the war, Indiana contributed approximately 210,000 soldiers and millions of dollars of equipment and supplies to the Union. Residents of Indiana, also known as Hoosiers, served in every major engagement of the war and almost every engagementminor or otherwisein the western theater of the war. Indiana, an agriculturally rich state containing the fifth-highest population in the Union and sixth-highest of all states, was critical to Northern success.
Northern Exclusion of Blacks
Indiana in the American Civil War - Wikipedia, the free encyclopedia