Thousands gather for Martin Luther King Jr. Day march in Seattle

Thousands have gathered to honor Martin Luther King Jr. on what would have been his 89th birthday.

The annual MLK Day Celebration in Seattle started at Garfield High School Monday morning.

A rally was held at the school at 23rd Avenue at East Jefferson Street. Seattle Mayor Jenny Durkan, Seattle Police Department staff and advocates were among the thousands in attendance.

Marchers headed into downtown Seattle at 12:30 p.m.

Some are wearing shirts that say "Take a Knee for Justice" -- the theme for this year's celebration -- in reference to the controversial move by many NFL players to kneel during the national anthem.

MORE: Martin Luther King Jr. Day events in Seattle, Bellevue & Tacoma

The group will head north on 23rd to Union Street, head west to 14th, north to Pine and then west on Pine to Westlake Park on Fourth Avenue. See a map of the march route here.

Once at Westlake, a rally will be held from about 1:30 p.m. to 2:30 p.m.

King County was originally named after William Rufus King, then renamed in 1986 by the county council after Dr. Martin Luther King Jr. to honor his legacy.  The renaming of the county did not become official until legislation succeeded in 2005. After a design process, a new logo was unveiled in 2007.