Marie Delphine Macarty was born on March 19, 1787, in New Orleans, Spanish Louisiana, as one of five children. Her father, Louis Barthélemy de McCarty, originally came from Ireland. He moved the family to New Orleans around 1730. Her mother was Marie Jeanne L'Érable, who was also known as "the widow Le Comte" due to her second marriage to Louis. Both of Delphine's parents were well-known in New Orleans' European Creole community. Her uncle by marriage, Esteban Rodríguez Miró, served as governor of Spanish Louisiana and Florida from 1785 to 1791. Additionally, her cousin, Augustin de Macarty, was mayor of New Orleans from 1815 to 1820.

Delphine was just four years old when the Haitian Revolution began in 1791, which frightened slaveholders in the American South and the Caribbean. This fear led to harsher treatment of enslaved people. Her uncle had been killed by his slaves many years before, and the revolution caused significant anxiety among slave owners in the region.

At the age of 13, on June 11, 1800, Delphine married Don Ramón de Lopez y Angulo. He was a high-ranking Spanish royal officer. They were married at the Saint Louis Cathedral in New Orleans. In 1804, after the United States acquired the territory, Don Ramón became consul general for Spain. Sadly, he died suddenly in Havana while Delphine was pregnant. After he passed away, Delphine returned to New Orleans with their daughter, Marie-Borja/Borgia, known as "Borquita."

Delphine married again in June 1808, this time to Jean Blanque, a banker, merchant, lawyer, and legislator. They moved into a house at 409 Royal Street, later named Villa Blanque. Together, they had four children: Marie Louise Pauline, Louise Marie Laure, Marie Louise Jeanne, and Jean Pierre Paulin Blanque. Jean Blanque passed away in 1816.

Delphine's third marriage took place on June 25, 1825, to Dr. Leonard Louis Nicolas LaLaurie, who was fifteen years younger. In 1831, Delphine acquired property at 1140 Royal Street and managed it independently. She built a two-story mansion there in 1832, which included slave quarters. Delphine played an active role in New Orleans society, often seen with her husband and two of her daughters.

However, her marriage had difficulties. On November 16, 1832, Delphine sought a legal separation from Dr. LaLaurie, claiming he treated her poorly. Her children supported her claims. Though the separation might not have been permanent, Dr. LaLaurie was present on April 10, 1834, the day a significant fire broke out at their mansion.

Between 1831 and 1834, Marie Delphine Macarty, who became known as Madame LaLaurie, owned a mansion on Royal Street in New Orleans. During this time, there were many troubling accounts of how she treated the people she enslaved. Harriet Martineau, visiting in 1836, noted that those enslaved by LaLaurie appeared "haggard and wretched" compared to others. However, LaLaurie often acted polite in public concerning Black individuals and showed concern for their health.

Records from funeral registries show that 12 enslaved people died at the Royal Street mansion between 1830 and 1834. One of the deceased was Bonne, a cook who died in 1833, along with her four children. Other accounts suggest that there were rumors of LaLaurie’s mistreatment that led to legal reminders regarding her treatment of enslaved people. One story recounts an eight-year-old girl falling to her death from the roof to escape punishment from LaLaurie, with the girl buried on the premises.

On April 10, 1834, a fire started in LaLaurie’s kitchen. A 70-year-old cook, chained to the stove, later confessed to starting the fire as a suicide attempt. When rescuers arrived, they discovered several enslaved individuals in horrific conditions, including some who were severely mutilated. The findings led to outrage, and a mob attacked the mansion, destroying much of it.

After the fire, LaLaurie and her family fled New Orleans. They traveled to Mobile, Alabama, and later to Paris, where she lived in exile. The details of her life after the fire are limited. Some accounts suggest she considered returning to New Orleans but did not go back due to her family's disapproval. LaLaurie died in Paris, with conflicting reports about the exact date and circumstances.