Margaret Brent, one of 13 children from a landed gentry family, was born in England in 1601. Publicly her family was Church of England but privately, they were Catholic. In the late 1620s, older sister, Catherine left for Belgium to become a nun, bringing suspicion on the family. 

With little prospects for inheritance, brother Giles journeyed to the Catholic colony of Maryland, and Margaret, her sister Mary and brother Fulke arrived the next year, 1638, to start new lives. Fulke returned to England within a year. At Margaret's request, the three remaining siblings received land grants from Lord Calvert.  

As a well-connected, financially secure woman, Margaret found many opportunities to expand her wealth in Maryland. The Brent sisters established an estate in St. Mary's City, Sister's Freehold, where they grew tobacco. They also made money by importing indentured servants from England and selling their Indenture Contracts to other colonists. She also offered loans to new colonists who needed money to establish their farms or businesses. Margaret used her earnings to buy more land. She eventually accumulated about 1,800 acres. Margaret made many court appearances suing to reclaim debts that other colonists owed her. As an unmarried woman, she was permitted to represent herself in 124 court cases between 1642 and 1650 and she prevailed in every case.  

Margaret also gained political influence in Maryland. In 1641, after a Jesuit colonist saved his son's life, Piscataway chief Kittamaquand wanted to establish diplomatic relations with the colony government. He asked Margaret and Governor Leonard Calvert to raise his seven-year-old daughter Mary as a sign of his sincerity. Margaret and Governor Leonard Calvert were named as Mary's joint guardians. 

When Leonard Calvert returned to England to consult with his brother, Lord Baltimore, he left Giles Brent in charge of the Maryland Colony. In 1643, Margaret Brent married off her 11-year-old ward, Mary, to her own 37-year-old brother Giles. They may have been planning on inheriting Indian land. Mary Kittamaquand Brent died at age 22. 

In 1644, while Giles Brent was acting Governor, Protestant Richard Ingle raided St. Mary's, took Giles Brent prisoner, and returned him and several others in chains to London. During this time no mention is made of Mary Kittamaquand,  Two years later, Leonard Calvert returned with troops and recaptured St. Mary's. 

Leonard Calvert died in 1647 after naming Margaret Brent as the executor of his will, which put her in charge of the entire colony's finances. She liquidated Leonard Calvert's estate, which had been pledged to pay the colony's soldiers and negotiated a settlement. When that yielded insufficient money, she petitioned the court to be appointed Lord Baltimore's lawyer, then proceeded to sell off all of his assets to avoid a near mutiny. 

In 1648 she demanded that the General Assembly give her two votes, one as a planter/landowner, and the other as the governor's representative. Her request was rejected.  

When Lord Baltimore returned to the colony, he turned against the Brents for the marriage of his ward Mary Kittamaquand, the sale of his property, and Margaret's demand for voting rights. In 1650, Margaret left Maryland for Stafford in the Virginia colony, possibly under threat from Lord Baltimore. 

There are an Elementary School, Middle School, and Junior College in Maryland named for Margaret Brent.