-Klotski - Huarong Dao Daughter in the Box

A significant precursor of the Klotzki puzzle is the 19th century 15-puzzle, where fifteen wooden squares had to be rearranged. The 15-puzzle enjoyed immense popularity in western countries during the late 19th century. Around this time, patents appeared for puzzles using differently shaped blocks. Henry Walton filed U.S. Patent 516,035 in 1893 for a sliding puzzle of identically-shaped rectangles, which according to Edward Hordern, is the first known sliding puzzle with rectangular blocks. Frank E. Moss filed U.S. Patent 668,386 in 1900 for a sliding puzzle of six squares and four rectangles, which is one of the first known occurrences of sliding puzzle with non-equal blocks.