Nancy Maria Johnson died in Washington, D.C., at the age of 95. Her death marks the end of the life of the inventor of the hand-cranked ice cream freezer. She is buried at Oak Hill Cemetery in Washington, D.C.

William G. Young improved on the ice cream freezer patented by Nancy Johnson. Young's improvements included modifications to the handle and the internal spatula, enhancing the cooling process and speeding up the freezing of the ice cream.