WLS-TV and WBBM-TV reported as many as 150 protesters marched 2.5 miles from Union Park on the city's Near West Side to Boeing, which was closed for the day.
"The Boeing Company heard the word loud and clear that anti war demonstrators from all over the world were going to come to their headquarters to shut them down today. That's why they told their employees to stay home," protester Rachael Perrotta was quoted as saying by WLS. Security around the building was tight.
Protest organizer Andy Thayer said Boeing was targeted because the company is "making billions of dollars off of America's wars abroad, and this is money that could be going to schools and other urgently needed social services here in the city."
Police Superintendent Garry McCarthy said the protesters did not have a permit. Officers, including McCarthy, were accompanying the protesters.
"We have been doing this on a regular basis. It is not that big of a crowd. This is pretty easily managed by our guys," McCarthy said.
Marchers threw paper airlines, chanted "Shame on Boeing," and laid on the ground as if they were dead. They left the Boeing headquarters about 12:30 p.m. and headed east toward President Obama's campaign headquarters.
The march contrasted sharply with Sunday's violent protest that left several officers and demonstrators injured. WBBM reported 40 of the 50 protesters arrested Sunday were released early Monday by police as supporters camped outside the Belmont Avenue detective headquarters, waiving an upside down American flag waiting for the rest to be freed. Three protesters were charged with felonies.
"They are occupiers. They participated in the protest," Kaylynn Strain of Des Moines, Iowa, said, "and when you're an occupier, every other occupier is your brother or sister."
Before Monday's march started, about a dozen protesters relaxed on bleachers near a softball field as police wandered through the park, the Chicago Tribune reported.
Protester Grace Lloyd, one of the first demonstrators to arrive Monday, told the Tribune she was demonstrating because she was dissatisfied with U.S. economic policies.
Attorney Sarah Gelsomino of the National Lawyers Guild said Sunday's injuries to protesters were largely from baton strikes, including a broken collarbone, teeth knocked out, a broken nose and a gash to the head.
Occupy Chicago said about 500 out-of-town protesters were to go home later Monday. Buses were scheduled to leave about 6 p.m., WBBM reported.