They gathered Monday morning outside the Otis Collins Post Office on Pulaski.
The US Postal Service has been looking at the closure of processing centers and local post offices across the country including some in the Chicago area.
Opponents of the closings say people need their post offices to stay open.
"The Otis Grant Collins Post Office is the most optimal and beneficial in this location, because it serves many in the South Lawndale and North Lawndale communities and Little Village," said Raul Montes, Jr., community activist. "Take into consideration that many people don't have vehicles, are elderly and really depend on this postal service."
The opponents also suggest, if your post office is facing closure, to appeal to the independent Postal Regulatory Commission.