601-603 S. Walnut St.
Street number prior to 1925: 427 and 425 Walnut

Adam Mertes and his family arrived in Appleton in the late 1840's and were the first German Catholics. They welcomes worshipers into their home for mass before the first Catholic church (St. Mary's Catholic Church) was established.

The Mertes family built this large Italianate home in 1871. In 1889 John Adam Mertes and Miss Josephine Mertes lived at 603 (then 425.) The 1925 Appleton city directory lists Louis M. Stenger living at 601 and Karl Schuetter at 603.