Lutherans are one branch of Protestant Christianity and have been in America for almost 400 years. Historically they have immigrated to America from Lutheran countries in Europe, especially Germany and Scandinavia. Immigrants during the eighteenth century founded Lutheran congregations in the middle colonies, while westward expansion and further immigration from Europe centered Lutherans in the American Midwest. Lutherans formed regional and national denominations based on geography, ethnicity, and theological differences, In the twentieth century they continued to grow, and mergers reduced the numbers of denominations by 1988 to two major denominations: the Evangelical Lutheran Church in America and the Lutheran Church-Missouri Synod. In 2015 there were close to seven million Lutherans in America.