While Marie Laveau worshipped at Catholic Mass in St. Louis Cathedral, she likely practiced Vodou at Congo Square. While no official documents place Laveau at Congo Square, many eyewitness accounts reported seeing her there. Congo Square is an important site of spirituality in New Orleans and has become associated with Marie Laveau throughout the years.
Congo Square is located in Louis Armstrong Park at the corner of North Rampart and St. Peter streets. For much of its history, Congo Square was not much but a field. Its earliest use was as a public market space where people could sell wares or services. Enslaved Africans during the French colonial era were exempt from work on Sundays as codified in the Code Noir. On Sundays, enslaved people would participate in the market to gain personal money. It was in this meeting place that Africans and Afro-Creoles began to dance and perform their African culture, drawing the ever-curious eyes of Europeans and Americans. 
While no official records place Marie Laveau at Congo Square, it is very likely she had been there numerous times throughout her life. Catherine Henry, Laveau’s grandmother, earned money as a marchande, or street vendor, and probably frequented the markets at Congo Square with her young granddaughter in tow. Numerous WPA interviewees discussed Marie Laveau’s role in leading Congo Square dances on Sunday afternoon. One interview stated, “She come walkin’ into Congo Square wit’ her head up in the air like a queen. Her skirts swished when she walked and everybody step back to let her pass. All the people-white and colored- start sayin’ that’s the most powerful woman they is. They say, ‘There goes Marie Laveau!”  Another interviewee stated, “Sometimes them policemans tried to keep Marie Laveau out, but she jest hypnotized ‘em and walked in. She could do that to anybody what got in her way. I seen her make polices get down and bark like dogs.” 
Whether or not Marie Laveau led dances at Congo Square, this specific square would have held great importance from her. One block away in her home, she would have heard the drums and dancing at Congo Square if she was not already there. As the leader of the Vodou community in New Orleans, Congo Square would have held immense importance to Laveau, as this area was where enslaved people and free people of color could unapologetically celebrate their African heritage, even if just for a few hours. In a society where enslavers purposely repressed the ethnic and religious heritage of enslaved people, Congo Square was where many people learned about their African roots.