Thousands of people took to the streets in the United States
Protesters of all ages streamed onto the National Mall in Washington
Activists placed more than 45,000 white vases holding flowers in the National Mall
Horrific shootings at a Texas elementary school that killed 19 children and two teachers
Another horrific shootings at a New York supermarket that left 10 Black people dead
Student-led organization held a rally that drew hundreds of thousands of people to the nation's capital in March 2018
Four years later, the demonstration was marked by frustration at the lack of progress.
Gun violence has killed more than 19,300 people so far this year in United states
Outside of Washington, hundreds of other demonstrations were planned around the country Saturday, including in Parkland, where protesters carried signs with messages such as "Am I Next?
The majority of Americans support tighter gun laws,but opposition is a hurdle to major changes.