Intolerance of immigration was not only a problem in the 1850s.
There were major problems involving Italian immigration into the twentieth century. In 1919 and 1920, Attorney General A. Mitchell Palmer attempted to arrest and deport radical leftists, in a series of raids known as the Palmer Raids. Intolerance of immigration even continues today.
However, the Know-Nothing movement declined as the issues of slavery and secessions—which lead to the Civil War—became more important. Some Know-Nothings proposed amendments to the Massachusetts constitution; the process required more than one legislative session, and with successive elections the Know-Nothings lost control of the legislature.