In a week since the deadly shooting at a high school in Southeast Florida, students around the state and other parts of the country have staged demonstrations, walk-outs and marches.
More than 1,000 additional police officers from around Britain have been deployed to help the local force keep order as sectarian tensions flare over the annual marches by the protestant Orange Order.
A joint march is a rather uneasy last-minute compromise to try to avoid the controversy caused last year by marches carrying racist banners and chanting anti-semitic slogans.