In 1800, a Baltimore merchant named William Taylor sent his recently released indentured servant, John McDonogh, to New Orleans to work as a merchant on his behalf.  Having established himself as a merchant, McDonogh turned his attention to property acquisition. McDonough owned many enslaved people. McDonogh supported the American Colonization Society. 
Much of McDonogh's early financial success came from his merchant shipping business. Ships would sail from Baltimore to New Orleans laden with anchors, paints, hardware, molasses casks, hoops for hogsheads, glassware, bricks, bagging, rope, candles, provisions, and dry goods. In turn, McDonogh would send ships filled with cotton, sugar, molasses, flour, indigo, and logwood back to Baltimore. By the year 1804, McDonogh had reached the peak of his mercantile success. 
According to William Allen, McDonogh’s first biographer, McDonogh retired from mercantile life in 1807 and began his dealings in real estate.  It was in his land dealings that John McDonogh made his vast fortune. The first pieces of property McDonogh acquired were large tracts in West Florida, which he bought from the Spanish government.  Eventually, he had acquired so much land that he became the largest landowner in the United States at that time. 
In his dealings with land property, McDonogh developed a scheme to maximize profits from this ownership: he rented his properties in respectable neighborhoods to brothel owners. When the neighboring families moved away from their homes, McDonogh bought their properties for an affordable sum. He then evicted the brothels and rented the properties to reputable families again. As a landlord, McDonogh did little to maintain his properties, earning him a reputation as a slumlord. 
In 1850, John McDonogh died and he willed $2 million to Baltimore and New Orleans for the construction of public schools. His will also freed some of the enslaved people he owned, including arrangements to send them to Africa. His heirs contested the will, which held up the execution of the will until 1858. This legal battle, ‘McDonogh’s Executors v. Murdoch’, went all the way to the Supreme Court. The court ruled against the heirs, allowing for the erection of a large number of John McDonogh schools in New Orleans.  New Orleans was granted $704,440. Overtime, 30 schools were built in New Orleans with this fund. Many of the schools were named “McDonogh” with a number after it.
In 1954, local educators and civil rights leaders Revis Ortique, Jr. and Arthur Chapital organized Black students and teachers to boycott an annual ceremony honoring McDonogh, one of the city's first protests of the civil rights era.  In the 1980s and '90s, many of the school's names were changed due to the controversy of McDonogh's slaveholding past. [2, 6]
During his lifetime, McDonogh was known as a miser. Even his obituary recounted, “[m]any traits of benevolence are cited to him on good authority, notwithstanding the general opinion to the contrary.” 
McDonogh was buried in the McDonoghville Cemetery, which sits on his massive former property in what is now Algiers Point. As the Times-Picayune reported, “Mr. McDonogh was buried yesterday afternoon in the cemetery erected by himself, near his residence, at McDonoghville, for his negroes. It was his wish that he should be buried among them.” McDonogh has a complex legacy, and is remembered both for his exploitation of the brothel system and enslaved people during his lifetime, along with his philanthropic donations upon his death.