Strong served on the Supreme Court until December 14, 1880, when he retired despite still being in good health, partly to set an example for several infirm justices who refused to give up their seats. He resumed the practice of law and pursued religious causes until his death, at Lake Minnewaska in Ulster County, New York, on August 19, 1895. Following funeral services at the chapel of the Charles Evans Cemetery in Reading, Pennsylvania, he was laid to rest at that cemetery. The Historical Society of Berks County has in its collection a few pieces relating to Justice Strong.