Complex sentence: On June 25,1895, the Post Office name was changed to the one word "Santaclaus," but the name was changed back to Santa Claus on February 17,1928.
Split into simpler sentences: On June 25,1895, the post office name was changed to the one word "Santaclaus". The name was changed back to "Santa Claus" on February 17,1928.