Before the French colonized Louisiana, Native Americans lived on the land that is now City Park. Bayou St. John, which runs through the park today, was part of a trade route commonly used by the Chapitoulas and the Houmas. After the French began to settle along the Gulf Coast in 1699, the indigenous peoples introduced the Louisiana colony's founding brothers, Iberville and Bienville, to the bayou as a short route connecting Lake Pontchartrain to the Mississippi River. Travelers could travel by boat most of the way and portage along a trail, bypassing the powerful Mississippi River currents. This trail led to the crescent of land that two decades later Bienville would choose as the site of New Orleans.
In the late 1700s, the Allard family took possession of the land on Bayou St. John to develop a plantation. In 1829, Louis Allard and his sister, Lise, mortgaged the plantation along with the enslaved people forced to work there for $27,500. In 1845, following a default on the mortgage, John McDonogh, a businessman, slaveholder, and philanthropist, bought the remaining property at a sheriff's sale for $40,500.
In 1850, John McDonogh willed the land to the cities of New Orleans and Baltimore. Around the same time, a movement within the United States sought to improve cities by constructing urban parks as a sanctuary from the squalor and congestion of the city life. Only one year after McDonogh's passing, the Daily Picayune identified a need for a public park in the rearmost part of the city, close to Lake Pontchartrain.
In 1859, the matter of the deed to the McDonogh land, shared by the cities of New Orleans and Baltimore, was resolved. Money changed hands and the city of New Orleans solely possessed the Allard tract. Although declared a public park in the 1850's, it remained largely undeveloped until the late 1890's because of the questionable business practices of the Governor of Louisiana and park commissioners during the 1870's.