Rosalie Stier was born in 1778 in Antwerp, in what was then the Austrian Netherlands, the third child of investment banker Henri Stier and his wife Marie-Louise Peeters. She was educated first by private tutors and then for four years at the convent school of the Holy Sepulchre in Liège. In 1794, with the French Revolutionary Army bearing down on their native Flanders, the Stier family fled Antwerp for the United States. The eight-member family, consisting of Rosalie, her parents, her brother and wife, her sister and husband and their child, sailed aboard a specially chartered ship with two servants, a large amount of gold, and a renowned art collection, sixty-three Old Master paintings by Rubens, Van Dyke, Brueghel and others entrusted to them for safe-keeping in America.

Landing in Philadelphia, the Stiers made their way to Annapolis where they lived for six years, renting the Paca House for much of this time. Here Rosalie Stier met George Calvert, tobacco planter and legislator from Prince George's County, Maryland, and a descendant of the Lords Baltimore, proprietors of the Maryland colony. They were married in 1799, and Calvert took Rosalie to live at his Mount Albion plantation on the Patuxent River.

With Rosalie married and her siblings and their families residing in Alexandria, the Stier parents decided in 1801 to make a permanent home for themselves, closer to the Washington, the new capital of the country. They began construction of their country estate , Riversdale, near the old port city of Bladensburg. The house was only partially finished, however, when it became necessary for the entire Stier family, except for Rosalie, to return to Europe. In 1803 Rosalie and George Calvert moved into Riversdale plantation, with the promise that it would be hers when it was finished. From Riversdale Rosalie Calvert began a correspondence with her European family that lasted for the next eighteen years until her death in 1821.

Mrs. Calvert's letters vividly chronicle the life of a busy plantation mistress and the early days of the new republic as seen through the eyes of a cultivated European woman. She had entrée into the highest levels of Washington and Maryland society, and her comments on the policies and politics of the day are informed and cogent.

The Calverts had nine children, five of whom survived to adulthood. Their oldest son, George Henry Calvert (1803-1889), was a noted author of his day; their second son, Charles Benedict Calvert (1808-1864), served one term (1861-1863) in the U.S. House of Representatives and founded the Maryland Agricultural College, now the University of Maryland. Riversdale, Mrs. Calvert's home, is now an historic house museum located in the town of Riverdale Park, Maryland.

Callcott, Margaret L., ed. Mistress of Riversdale: The Plantations Letters of Rosalie Stier Calvert, 1795-1821. Baltimore: Johns Hopkins University Press, 1991.