PHOTOS: Students participate in 'March for our Lives' throughout the country LOS ANGELES, CA - MARCH 22: Young activists paint signs to be carried at the upcoming March for Our Lives Los Angeles on March 22, 2018 in Los Angeles, California. More than 500,000 are expected to march for gun control at rallies nationwide on March 24. The marches have been organized by students from Marjory Stoneman Douglas High School where 17 people were killed in a mass shooting February 14. (Photo by Mario Tama/Getty Images)Photo by: Mario Tama PHOTOS: Students participate in 'March for our Lives' throughout the country LOS ANGELES, CA - MARCH 22: Young activists paint signs to be carried at the upcoming March for Our Lives Los Angeles on March 22, 2018 in Los Angeles, California. More than 500,000 are expected to march for gun control at rallies nationwide on March 24. The marches have been organized by students from Marjory Stoneman Douglas High School where 17 people were killed in a mass shooting February 14. (Photo by Mario Tama/Getty Images)Photo by: Mario Tama PHOTOS: Students participate in 'March for our Lives' throughout the country LOS ANGELES, CA - MARCH 22: Young activists prepare signs to be carried at the upcoming March for Our Lives Los Angeles on March 22, 2018 in Los Angeles, California. More than 500,000 are expected to march for gun control at rallies nationwide on March 24. The marches have been organized by students from Marjory Stoneman Douglas High School where 17 people were killed in a mass shooting February 14. (Photo by Mario Tama/Getty Images)Photo by: Mario Tama PHOTOS: Students participate in 'March for our Lives' throughout the country LOS ANGELES, CA - MARCH 22: An activist paints a sign to be carried at the upcoming March for Our Lives Los Angeles on March 22, 2018 in Los Angeles, California. More than 500,000 are expected to march for gun control at rallies nationwide on March 24. The marches have been organized by students from Marjory Stoneman Douglas High School where 17 people were killed in a mass shooting February 14. (Photo by Mario Tama/Getty Images)Photo by: Mario Tama