Complex sentence: Historian Tyler Anbinder warns, however, that the "Native American" party should not be confused with the Know-Nothings because the two different groups ran separate tickets in the same elections in the 1850s.
Split into simpler sentences: Historian Tyler Anbinder warns, however, that the "Native American" party should not be confused with the Know-Nothings. The two groups ran separate tickets in the same elections in the 1850s.