Properly known as Les Soeurs de la Charité de Montréal, they are also known as the "Grey Nuns" (Les Soeurs Grises). They were founded by Marguerite d'Youville in 1737.
The Sisters are driven by Marguerite's vision of universal charity and God's love for everyone. They work to provide help for all of the poor and neglected in society. This mission is driven by "courageous faith" - leading them to take risks in representing the rights of the poor and the sacredness of all life. They work throughout North, Central, and South America, adapting their work to local needs, but always focusing on those who are not otherwise aided.
The Sisters are rights workers, environmental activists, educators, caregivers and more.
They care for the sick and disabled, the homeless and hungry, the addicted, the lonely and frail.
They look after the emotionally and psychologically distressed.
The care for battered women, the elderly, single mothers and abandoned children.
They provide spiritual support and encouragement to all who need it.
In addition to their work as individuals, the Sisters' organizations sponsor numerous health care facilities and medical programs in the Americas. Several affiliated apostolistic congregations (of the Roman Catholic Church (duh!)) make up the Soeurs Grises.
Saint Marguerite d'Youville was canonized by Pope John Paul II on December 9, 1990.
Primary sources (and for more info): http://www.sgm.qc.ca/ and www.sgmlex.org
Note: There's a lot to say about Marguerite d'Youville. I highly recommend researching her life story as a noding task.
You could start at: http://www.sgm.qc.ca/young-adult/my_en.htm. Please let me know if you do.