The SLUMP surname was adopted in Lemsterland, Friesland, The Netherlands in 1812. Prior to this, the family used patronyms. Ancestors were in Overijssel and Drenthe in previous generations. Related men, unbeknownst to their other family members, may have adopted different surnames. Immigrants to the United States adopted different surnames, including Slumpff, Stumpf, and Tavares. Thus, the project will admit men who had Y-DNA matches, even thought their surname may not be SLUMP.