The march began at about 10 a.m. in MacArthur Park and was expected to end at the Federal Building in downtown L.A.
Within the first 30 minutes, the river of demonstrators forced law enforcement to shut down several on-ramps and off-ramps of both sides of the 110 and 101 freeways in downtown.
Authorities from the LAPD and other law enforcement agencies said although it's been the largest demonstration in the area so far, protesters have marched peacefully and respectfully.
About 187 people, eight of them juveniles, were arrested during a protest made up of about 1,000 demonstrators marching through downtown L.A. Friday night, according to the LAPD.
Marchers took off from Pershing Square, starting a miles-long march through the city.
The group made multiple attempts to get onto the 110 and 101 freeways but were blocked by authorities.
A little after 8 p.m. they ended their march for a short time and arrived in front of City Hall. Many people held signs and gathered on the steps and sidewalk.
"We've all made a huge mistake, refuse to accept it," protester Hunter Pritchett said of the presidential election's outcome.
The demonstrators, some of whom carried a banner reading "#NOTMYPREZ," then made their way back to Pershing Square and continued on to L.A. Live before turning northward again.
A man in the crowd was seen spray-painting a Los Angeles Police Department vehicle. About 20 minutes later, he was taken into custody by officers in riot gear.