When did the native American removal end?

Hard to pin down really. The largest forced removal was of the Southeastern tribes (Cherokee, Creek, et al) in the 1830's "Trail of Tears." Despite a Supreme Court decision that allowed them to stay where they were, Present Andrew Jackson ignored the decision and ordered the Army to move them west into Oklahoma Territory. After that, most Indian removal was really a matter of Indian being told they could stay on certain portions of their land and then having the US Government go back on the promises when they wanted the land for whites. This trended to push the Indians into smaller and smaller pockets of territory (reservations). Many tribes rebelled against this treatment from the mid 1800's to the end of the century. The last Battle of these Indian Wars was at Wounded Knee in 1890. This was not really a battle, since the US troops simply attacked an Indian camp with warning one morning and killed everyone in sight including women and children.