The Catholic Church in the United States began in the colonial era, but by the mid-1800s, most of the Spanish, French, and Mexican influences had demographically faded in importance, with Protestant Americans moving west and taking over many formerly Catholic regions. Small Catholic pockets remained in Maryland, Alabama, Florida, and Louisiana, but scarcely anywhere else.

However, after 1840, American Catholicism grew through immigration from Europe, especially from Germans and Irish. After 1890, Catholic immigrants from Southern and Eastern Europe arrived in large numbers. The Church set up an elaborate infrastructure, based on local parishes organized into dioceses run by bishops appointed by the Pope. Each diocese set up a network of schools, colleges, hospitals, orphanages and other charitable institutions.

Many priests and nuns arrived from France and Ireland. By 1900, America was producing a sufficient supply of priests and nuns. The Catholic population was primarily working-class until after World War II when it increasingly moved into white-collar status and left the inner city for the suburbs. After 1960, the number of priests and nuns fell rapidly and new vocations plunged. However, the Catholic population was sustained by a large influx from Mexico and Central America.

As the Catholic colleges and universities matured, questions were raised about their adherence to orthodox Catholic theology. After 1980, the Catholic bishops became involved in politics, especially on issues relating to abortion and sexuality.

In the 2014, the Religious Landscape Survey published by the Pew Research Center, 20.8% of Americans identified themselves as Catholic. By 2016, 26% of Catholics had college degrees, and 36% of them earned over $100,000.http://www.pewresearch.org/fact-tank/2016/11/04/ the-most-and-least-educated-u-s-religious-groups/ and http://www.pewresearch.org/fact/-tank-/2016/11/04/the-most-and-least-educated-u-s-religious-groups/

Colonial era In general The history of Catholicism in the United States – prior to 1776 – often focuses on the 13 English-speaking colonies along the Atlantic seaboard, as it was they who declared independence from Great Britain in 1776, to form the United States of America. However, this history – of Catholicism in the United States – also includes the French and Spanish colonies, because they later became part of the contiguous United States. These Catholics were centered in what became Florida, Texas, California, Puerto Rico and much of rest of the Southwest.

Most of the Catholic population in the United States during the colonial period came from England, Germany, and France, with approximately 10,000 Irish Catholics immigrating by 1775, and they overwhelmingly settled in Maryland and Pennsylvania. In 1700, the estimated population of Maryland was 29,600, about one-tenth of which was Catholic (or approximately 3,000). By 1756, the number of Catholics in Maryland had increased to approximately 7,000, which increased further to 20,000 by 1765. In Pennsylvania, there were approximately 3,000 Catholics in 1756 and 6,000 by 1765. By the end of the American Revolutionary War in 1783, there were approximately 24,000 to 25,000 Catholics in the United States out of a total population of approximately 3 million.

The current dioceses of the United States are derived from a number of colonial-era dioceses. The following traces the succession of dioceses up to the first diocese that was completely contained in United States territory.

Spanish dioceses gave rise to many successors in the United States: The Spanish parts of the mainland United States were originally part of the Diocese of Mexico established in 1530, and later the Diocese of Durango when it split in 1620. California became part of the Diocese of Sonora in 1779. The Diocese of Both Californias, based in San Diego, was established in 1840. After the Mexican–American War, the Mexican portion was split off in 1849, with the United States portion becoming the Diocese of Monterey. New Mexico remained part of the Diocese of Durango until after it was annexed by the United States, with the Diocese of Santa Fe established in 1850. Texas was organized into a prefecture apostolic in 1839, which became the Diocese of Galveston in 1847. Although the French parts of the current United States were originally part of the Diocese of Quebec, after the French and Indian War this was transferred to the Diocese of Santiago de Cuba and later the Diocese of San Cristóbal de la Habana when it was created in 1787. In 1793, the Diocese of Louisiana and the Floridas was created, which was later renamed the Diocese of New Orleans. Puerto Rico was originally under the jurisdiction of the Diocese of Seville in Spain. The Diocese of San Juan de Puerto Rico was established in 1511. Guam and the Northern Mariana Islands were originally part of the Diocese of Cebu in the Philippines. They were split into the Apostolic Prefecture of Mariana Islands in 1902, which became the Diocese of Agaña in 1965. The English parts were originally under the jurisdiction of the Apostolic Vicariate of the London District. After the American Revolution, the Apostolic Prefecture of the United States was established in 1784, which became the Diocese of Baltimore in 1789. The Vicariate Apostolic of the Oregon Territory was established in 1843. In 1846, the United States part of Oregon Territory became the Diocese of Oregon City. The remainder became the Canadian Diocese of Vancouver Island, from which the Prefecture Apostolic of Alaska was created in 1894. Part of it became the Diocese of Juneau in 1951, with the rest becoming the Diocese of Fairbanks in 1962. The Apostolic Vicariate of Eastern Oceania was established in 1833. Part of this was split into the Vicariate Apostolic of the Sandwich Islands in 1843, which became the Diocese of Honolulu in 1941. Another part was split into the Apostolic Vicariate of Central Oceania in 1842. This became the Diocese of Apia, which included both Samoa and American Samoa, in 1966. In 1982, the American Samoa part was split into the Diocese of Samoa–Pago Pago.

Spanish missions

Catholicism first came to the territories now forming the United States by way of Spanish colonists in the present-day Virgin Islands (1493), Puerto Rico (1508), Florida (1513), South Carolina (1566), Georgia (1568–1684), and the southwest. The first known Catholic Mass held in what would become the United States was in 1526 by Dominican friars Antonio de Montesinos and Anthony de Cervantes, who ministered to the San Miguel de Gualdape colonists for the 3 months the colony existed.Schroeder, Henry Joseph. "Antonio Montesino." The Catholic Encyclopedia. Vol. 10. New York: Robert Appleton Company, 1911. 26 Jun. 2014

The influence of the Alta California missions (1769 and onwards) forms a lasting memorial to part of this heritage. Until the 19th century, the Franciscans and other religious orders had to operate their missions under the Spanish and Portuguese governments and military.Franzen, 362 Junípero Serra founded a series of missions in California which became important economic, political, and religious institutions.Norman, The Roman Catholic Church an Illustrated History (2007), pp. 111–2 These missions brought grain, cattle and a new way of living to the Indian tribes of California. Overland routes were established from New Mexico that resulted in the colonization and founding of San Diego at Mission San Diego de Alcala (1760), Mission San Carlos Borromeo de Carmelo at Carmel-by-the-Sea, California in (1770), Mission San Francisco de Asis (Mission Dolores) at San Francisco (1776), Mission San Luis Obispo at San Luis Obispo (1772), Mission Santa Clara de Asis at Santa Clara (1777), Mission Senora Reina de los Angeles Asistencia in Los Angeles (1784), Mission Santa Barbara at Santa Barbara (1786), Mission San Juan Bautista in San Juan Bautista (1797), among numerous others.

French territories

In the French territories, Catholicism was ushered in with the establishment of missions such as Sault Ste. Marie, Michigan (1668), St. Ignace on the Straits of Mackinac, Michigan (1671) and Holy Family at Cahokia, Illinois (1699) and then colonies and forts in Detroit (1701), St. Louis, Mobile (1702), Kaskaskia (1703), Biloxi, Baton Rouge, New Orleans(1718), and Vincennes (1732). In the late 17th century, French expeditions, which included sovereign, religious and commercial aims, established a foothold on the Mississippi River and Gulf Coast. Small settlements were founded along the banks of the Mississippi and its major tributaries, from Louisiana to as far north as the region called the Illinois Country.Richard Middleton, Colonial America (Oxford: Blackwell Publishing, 2003), 407.

The French possessions were under the authority of the diocese of Quebec, under an archbishop, chosen and funded by the king. The religious fervor of the population was very weak; Catholics ignored the tithe, a 10% tax to support the clergy. By 1720, the Ursulines were operating a hospital in New Orleans. The Church did send Companions of the Seminary of Quebec and Jesuits as missionaries, to convert Native Americans. These missionaries introduced the Natives to Catholicism in stages.

English colonies Catholicism was introduced to the English colonies with the founding of the Province of Maryland. Maryland was one of the few regions among the English colonies in North America that had a sizable Catholic population. However, the 1646 defeat of the Royalists in the English Civil War led to stringent laws against Catholic education and the extradition of known Jesuits from the colony, including Andrew White, and the destruction of their school at Calverton Manor. Due to immigration, by 1660 the population of the Province had gradually become predominantly Protestant. During the greater part of the Maryland colonial period, Jesuits continued to conduct Catholic schools clandestinely.

Maryland was a rare example of religious toleration in a fairly intolerant age, particularly amongst other English colonies which frequently exhibited a militant Protestantism. The Maryland Toleration Act, issued in 1649, was one of the first laws that explicitly defined tolerance of varieties of Christianity. It has been considered a precursor to the First Amendment.

After Virginia established Anglicanism as mandatory in the colony, numerous Puritans migrated from Virginia to Maryland. The government gave them land for a settlement called Providence (now called Annapolis). In 1650, the Puritans revolted against the proprietary government and set up a new government that outlawed both Catholicism and Anglicanism. The Puritan revolt lasted until 1658, when the Calvert family regained control and re-enacted the Toleration Act.

Origins of anti-Catholicism American anti-Catholicism and Nativist opposition to Catholic immigrants had their origins in the Reformation. Because the Reformation, from the Protestant perspective, was based on an effort by Protestants to correct what they perceived to be errors and excesses of the Catholic Church, it formed strong positions against the Catholic interpretation of the Bible, the Catholic hierarchy and the Papacy. "To be English was to be anti-Catholic," writes Robert Curran.Robert Emmett Curran, Papist Devils: Catholics in British America, 1574-1783 (2014) pp 201-2 These positions were brought to the eastern seaboard of the New World by British colonists, predominantly Protestant, who opposed not only the Catholic Church in Europe and in French and Spanish-speaking colonies of the New World, but also the policies of the Church of England in their own homeland, which they believed perpetuated Catholic doctrine and practices, and, for that reason, deemed it to be insufficiently reformed.