On May 5, 1970, an estimated 1,000 people surge onto southbound lanes of the Interstate 5 Freeway to protest the recent invasion of Cambodia and the deaths of four antiwar protesters on the Kent State campus in Ohio the previous day.
The protest began that morning on the campus of the University of Washington. A large mass of demonstrators then left campus and marched north on University Way NE. They turned west on NE 45th St. and approximately 1,000 entered the freeway. The group halted all traffic as they moved south over the Freeway Bridge. They were met on the far side by a handful of State Troopers and exited peacefully at the Roanoke Street off-ramp.
More than 10,000 protesters tried to duplicate the "Freeway March" on the following day, but were repulsed by State Troopers and police with tear gas and clubs. On May 8, Mayor Wes Uhlman (b. 1935) closed the I-5 Express Lanes for a sanctioned protest march from downtown Seattle to the University District by some 15,000 demonstrators.