"Small-scale migration to the U.S. by Muslims began in 1840, with the arrival of Yemenites and Turks, and lasted until World War I. Most of the immigrants, from Arab areas of the Ottoman Empire, came with the purpose of making money and returning to their homeland. However, the economic hardships of 19th-Century America prevented them from prospering, and as a result the immigrants settled in the United States permanently. These immigrants settled primarily in Dearborn, Michigan; Quincy, Massachusetts; and Ross, North Dakota. Ross, North Dakota is the site of the first documented mosque and Muslim Cemetery, but it was abandoned and later torn down in the mid 1970s. A new mosque was built in its place in 2005.
- 1906 Bosnian Muslims in Chicago, Illinois started the Jamaat al-Hajrije (Assembly Society; a social service organization devoted to Bosnian Muslims). This is the longest lasting incorporated Muslim community in the United States. They met in coffeehouses and eventually opened the first Islamic Sunday School with curriculum and textbooks under Imam Kamil Avdih (a graduate of al-Azhar and author of Survey of Islamic Doctrines).
- 1907 Lipka Tatar immigrants from the Podlasie region of Poland founded the first Muslim organization in New York City, the American Mohammedan Society .
- 1915, what is most likely the first American mosque was founded by Albanian Muslims in Biddeford, Maine. A Muslim cemetery still exists there.
- 1920 First Islamic mission station was established by an Indian Ahmadiyya Muslim missionary, followed by the building of the Al-Sadiq Mosque in 1921.
- 1934 The first building built specifically to be a mosque is established in Cedar Rapids, Iowa.
- 1945 A mosque existed in Dearborn, Michigan, home to the largest Arab-American population in the U.S.
Construction of mosques sped up in the 1920s and 1930s, and by 1952, there were over 20 mosques. Although the first mosque was established in the U.S. in 1915, relatively few mosques were founded before the 1960s. Eighty-seven percent of mosques in the U.S. were founded within the last three decades according to the Faith Communities Today (FACT) survey. California has more mosques than any other state."