Catholic sisters and nuns in the United States have played a major role in American religion, education, nursing and social work since the early 19th century. In Catholic Europe, convents were heavily endowed over the centuries, and were sponsored by the aristocracy. Religious orders were founded by entrepreneurial women who saw a need and an opportunity, and were staffed by devout women from poor families. The number of Catholic nuns grew exponentially from about 900 in the year 1840, to a maximum of nearly 200,000 in 1965, falling to 56,000 in 2010. According to an article posted on CatholicPhilly.com, the website of the Archdiocese of Philadelphia, Pennsylvania, in October 2018, National Religious Retirement Office statistics showed that number as 47,160 in 2016, adding that “about 77 percent of women religious are older than 70.” In March 2022, the NRRO was reporting statistics from 2018, citing the number of professed sisters as 45,100. The network of Catholic institutions provided high status lifetime careers as nuns in parochial schools, hospitals, and orphanages. They were part of an international Catholic network, with considerable movement back and forth from Britain, France, Germany and Canada.NELSON, SIOBAN. Say Little, Do Much: Nursing, Nuns, and Hospitals in the Nineteenth Century. University of Pennsylvania Press, 2001. Accessed December 22, 2020. http://www.jstor.org/stable/j.ctt3fj4g2

Some American Catholics came to the defense of American sisters when the Vatican initiated an investigation into what it viewed as unorthodox leanings among the Leadership Conference of Women Religious. The controversial investigation, which was viewed by many U.S. Catholics as a "vexing and unjust inquisition of the sisters who ran the church's schools, hospitals and charities" was ultimately closed in 2015 in meeting with Pope Francis.Vatican Ends Battle With U.S. Catholic Nuns’ Group NYT, April 16, 2015

History The first women religious in what would become the United States, were fourteen French Ursuline nuns who arrived in New Orleans in July 1727,Blondeau, Caherine. Étude normande: La vie littéraire à Rouen au 18ème siècle: "Le Mississipy est en cet endroit plus large que n'est la rivière de Seine à Roüen", à propos de la Relation du voyage des dames religieuses Ursulines de Roüen à la Nouvelle Orléans, p. 50. and opened Ursuline Academy, which continues in operation and is the oldest continuously operating school for girls in the United States.

The Sisters of Saint Anne are a Roman Catholic religious institute, founded in 1850 in Vaudreuil, Quebec, Canada, by the Blessed Marie Anne Blondin, S.S.A. The Sisters arrived in the United States in September 1867 at the request of the Bishop of Buffalo, opening a school in Oswego, New York. Between 1840 and 1930 approximately 900,000 Quebec residents, most of them French Canadian left for the United States. Textile manufacturing centers and other industrial towns such as Lewiston, Maine, Fall River, Massachusetts, Woonsocket, Rhode Island and Manchester, New Hampshire attracted significant French-Canadian populations. The Sisters went on to expand throughout northern New York and New England, staffing many schools of French-speaking parishes.

American communities The Daughters of Charity of St. Vincent de Paul were founded as the Sisters of Charity of St. Joseph in 1809 in Emmitsburg, Maryland by Elizabeth Ann Seton, who had hoped to establish a community of Daughters of Charity founded in France by St. Vincent de Paul in 1633. Unable to do so because of the political situation during the Napoleonic Wars, she adopted the Rules of the Daughters of Charity. The institute established other communities elsewhere, many of which subsequently became independent. In 1850 the community at Emmitsburg affiliated with the Mother House of the Daughters of Charity in Paris and at that time adopted the blue habit and the white collar and cornette. The community in Emmitsburg became the first American province of the Daughters of Charity. In 1817, Mother Seton sent three Sisters to New York at the invitation of Bishop Connolly to open a home for dependent children. In 1846 the New York congregation incorporated as a separate order, the Sisters of Charity of New York. The Sisters in New York retained the rule, customs, and spiritual exercises established by Mother Seton, and her black habit, cape and cap. In 1869 they established The New York Foundling, an orphanage for abandoned children,Sisters of Charity of New York Timeline and in 1880 opened St. Ann's Hospital to provide medical treatment for unmarried mothers. In 1854 the New York Children's Aid Society began sending orphans and neglected children to live outside the city. The majority were sent to the West and Midwest. In 1875, the Sisters initiated a similar program working in conjunction with priests throughout the Midwest and South in an effort to place these children in Catholic families. The Foundling Hospital sent infants and toddlers to prearranged Roman Catholic homes from 1875 to 1919.Warren, Andrea. "The Orphan Train", The Washington Post, 1998 By the 1910s 1,000 children a year were placed with new families.Creagh, Dianne. "The Baby Trains: Catholic Foster Care and Western Migration, 1873-1929," Journal of Social History (2012) 46#1 pp 197-218 The Dominican Sisters of Peace trace their heritage to the original Dominican foundation in America, the Dominican Sisters of St. Catherine of Sienna, founded in 1822 in Springfield, Kentucky.Dominicans at Home in a Young Nation: 1786-1865, >(McGreal, Mary Nona, ed.) Strasbourg, France: Editions du Signe, 2001 In 2009 seven Dominican congregations merged to form the new Dominican Sisters of Peace. The seven were: the Dominican Sisters of St. Catharine, KY; Dominican Sisters of Akron, Ohio; Dominican Sisters of St. Mary of the Springs, Columbus, Ohio; Dominican Sisters of Great Bend, Kansas; Dominican Sisters of Oxford, Michigan; Dominican Sisters of St. Mary's, New Orleans and the Eucharistic Missionaries of St. Dominic, New Orleans, Louisiana. In 2012. In 2012 the Dominican Sisters of St. Catherine de’ Ricci also joined. The Sisters of the Divine Compassion are a Roman Catholic religious institute founded in New York City in 1886 by Mother Mary Veronica – formerly Mary Dannat Starr and Msgr. Thomas Preston.

Expansion before 1860 Historian Joseph Mannard has suggested that there was a "convent revolution" in Antebellum America. The number of orders and sisters grew rapidly. In 1830 there were only 10 orders in the U.S, with under 500 sisters. By 1860 45 orders had been added and there were over 5,000 sisters. In 1830 there were only 20 Catholic female academies in the U.S., by 1860 there were 201. In 1830 there was one sister-founded hospital in the U.S.. By 1860 there were 35. This increase in numbers was accompanied by an increasing public awareness of Catholic women religious.

Civil War The male doctors of the Civil War era were generally dubious about the civilian women volunteering to be nurses. However, they were generally appreciative of the Catholic orders of sisters that operated their own hospitals, and sent cadres to Army hospitals to help after bloody battles. Judith Metz, "In times of war," in Ursula Stepsis and Dolores Liptak, eds. Pioneer Healers: The History of Women Religious in American Health Care (19890 pp.39–57. George C. Stewart, Jr. Marvels of Charity: History of American Sisters and Nuns (1994) pp. 185–221.Mary Denis Maher, To Bind Up the Wounds: Catholic Sister Nurses in the U.S. Civil War (1989) online

When the Civil War broke out Mother Mary of St. Angela, C.S.C. organized a corps of the Sisters of the Holy Cross to care for the sick and wounded soldiers. She established hospitals, both temporary and permanent, and, when Generals failed to secure needed aid for the sick and wounded, she made trips to Washington on their behalf. In May 1861 Mother Mary Cecilia Bailly, S.P., Superior General of the Sisters of Providence of Saint Mary-of-the-Woods, sent Sisters to staff military hospitals in Indianapolis and Vincennes, Indiana. They also tended patients at the Confederate prison located in Indianapolis, which held at one time 7,000 prisoners. At the end of the war the Hospital was returned to the city, and the Sisters opened St John's Infirmary for those soldiers with no place to go, but not yet strong enough to travel. The Sisters of Providence are now honored by a monument in Washington, D.C., dedicated to the Nuns of the Battlefield of the Civil War. In June 1861 Sister Anthony O'Connell, S.C. was one of six Sisters of Charity of Cincinnati who went to Camp Dennison to provide nursing assistance. Sisters also served at Cumberland, Virginia, treating the wounded of both armies. More than one-third of the community, which by then had more than one hundred members, served. Sister Anthony developed the Battlefield Triage. Her method was "the first recognizably modern triage techniques in war zones, saved countless lives through faster hospital treatment and won her praise from President Lincoln". Her medical skills allowed her to intervene to save soldiers' limbs from amputation."Namesake", The Sons of Union Veterans of the Civil War, Sister Anthony O'Connell Auxiliary For her service at the Battle of Shiloh Sister Anthony became known as the "Angel of the Battlefield". Her portrait hangs in the Smithsonian Institution in Washington, DC. In 1862 the Sisters of Charity of New York began nursing Civil War wounded in St. Joseph's Military Hospital, at McGowan's Pass, the former site of Mt. St. Vincent in Central Park. The hospital closed in 1865. Mary Frances Schervier, S.P.S.F. of the Poor Sisters of St. Francis based in Aachen, Germany, visited the congregations communities in the United States in 1863, and helped her Sisters nurse wounded soldiers. St. Mary Hospital in Hoboken, New Jersey was founded for this work. The Congregation of the Sisters of Charity of the Incarnate Word, Houston is a religious institute of women begun in 1866 in Galveston, Texas, as Texas was suffering from the ravages of the Civil War, coupled with the tragedy of a rapidly spreading cholera epidemic. A second Community was started in San Antonio, in 1869, and is now the largest group of religious women in Texas. They founded San Antonio's first public hospital, known today as Christus Santa Rosa Hospital. They began educational work in 1874 and founded the University of the Incarnate Word in 1881.

Other communities who assisted the sick and wounded include: the Sisters of St. Joseph, Carmelites, Dominican Order, Ursulines, Sisters of Mercy, Congregation of the Sisters of Our Lady of Mercy, Daughters of Charity of St. Vincent de Paul, Sisters of Charity of Nazareth, and the Congregation of Divine Providence.

Hospitals The majority of these women followed an active apostolate; the number of contemplative communities being relatively small. About sixty percent were primarily involved with teaching, while the rest were engaged in nursing and administration in hospitals.The Catholic Church in the United States of America, Catholic Editing Company, New York, 1914