He began his career as an exceptionally tall person while a teenager, performing in a traveling circus, and appeared in the 1939 New York World's Fair.

He was employed as a giant Santa Claus and appeared on American television as a figure of high stature and in freak shows as the World's Tallest Man.

[2] Nacken began his career in show business performing as "Uranus" and the "giant from the Rhineland" in a German traveling circus.

[9] He returned to Germany at the beginning of World War II and was immediately drafted into the army, becoming their tallest soldier on record.

[7][15] In August 1949, newspapers announced Nacken was to return to the United States because he wanted to leave post-war Germany.

[17] Nacken and his wife emigrated to the United States on the SS Atlantic from Genoa, Italy,[1] arriving in the port of New York City on 6 December 1950.