Thomas Sloo Jr. began his career as a surveyor in Hamilton County, Illinois, where he contributed to the planning of McLeansboro. He transitioned into public service, being elected to the Illinois Senate, where he advocated for slavery. Sloo Jr. later served as one of the first five canal commissioners, overseeing significant infrastructure projects. After a move to New Orleans, he engaged in the commission business for two decades and held a role on the New Orleans city board of education. His professional journey reflects a blend of public service and infrastructure development.

Thomas Sloo Jr. emerges as a figure who adeptly navigates ideological waters, blending seemingly disparate policy positions. His advocacy for slavery in Illinois juxtaposes with his later infrastructural contributions, suggesting a calculated approach to regional development. Sloo Jr.'s transition from advocating for slavery to focusing on economic ventures in New Orleans hints at a strategic, perhaps opportunistic, political evolution. His involvement in both the Illinois and Michigan Canal project and the New Orleans city board of education reveals a multifaceted engagement with public infrastructure and education. This blend of positions prompts curiosity about how he reconciles these varied commitments.