During the Republic of Texas period, Europeans became interested in colonizing Texas. In the 1840s, a group of German noblemen formed the Adelsverein or the Society for the Protection of German Immigration in Texas. Prince Carl of Solms-Braunfels became the Adelsverein's first Commissioner General and founded New Braunfels on March 21, 1845.
Prince Carl chose this hill property overlooking the city as the site for a fortress to protect the city. He named it the Sophienburg in honor of his fiancée, Princess Sophia. Although a log structure was built to serve as the Adelsverein headquarters, a large fortress was never built. A well was dug and other structures were built on the property that served as Adelsverein storehouses and lodging. Prince Carl returned to Germany a month after the founding of New Braunfels and John O. Meusebach succeeded him as Commissioner General. The Adelsverein had financial trouble and the Sophienburg Hill property was sold and divided. Eventually, the buildings deteriorated and in 1886, a storm destroyed the last remaining log structure.
In 1933, a portion of the original Sophienburg property was purchased to build the first museum building that still stands at the corner of Academy and Coll. In 1938, the first city library was built adjacent to the museum
with a second library built nearby in 1968. These structures house the Sophienburg Museum and Archives collections. The Sophienburg Museum Association has ensured that the campus reflects the history of German immigration, the town's founding and its ongoing growth.