In 1845, Prince Carl of Solms-Braunfels and a group of emigrants set out from Germany to find a new home in Texas. The Prince chose a site on the Comal River because of its abundant water, lush vegetation, and "a good omen." There he and his band of pioneers founded New Braunfels.

For his personal home Prince Carl chose a hill overlooking the beginnings of the town and began his plan to build a castle on the site. His home was to be called Sophienburg — Sophie's Castle — for his fiancée, Lady Sophia, Princess of Salm-Salm. However, when he returned to Germany to bring Sophia to Texas, she refused to leave. In a move that baffles native Texans to this day, Prince Carl chose his fiancée over Texas and stayed Germany to marry Sophia. He never returned to Texas.

Today, the Sophienburg Museum and Archives resides on the hill chosen long ago by Prince Carl.