I was going with your example of 1866 which was after ratification. Kentucky was the last Union state to ratify it in 1976.

Oregon (December 8, 1865)
California (December 19, 1865)
Florida (December 28, 1865, reaffirmed on June 9, 1869)
Iowa (January 15, 1866)
New Jersey (January 23, 1866, after having rejected it on March 16, 1865)
Texas (February 18, 1870)
Delaware (February 12, 1901, after having rejected it on February 8, 1865)
Kentucky (March 18, 1976, after having rejected it on February 24, 1865)
Mississippi (March 16, 1995, after having rejected it on December 5, 1865)