Donors to the shoe monument include actresses Susan Sarandon and Bette Midler, and talk show host Chelsea Handler.
Event organizers claimed the 7,000 pairs of shoes - 14,000 shoes altogether - symbolized the 7,000 children killed in the U.S. between December 14, 2012 and March 13, 2018.
Explaining the meaning behind the installation, he said, "There's nobody in those shoes, it's like the emptiness in our hearts from gun violence".
"I'll travel to D.C. literally wearing my son Daniel's shoes, the ones he wore the day he died at Columbine", said Tom Mauser.
Students across the country plan to walk out of their classrooms for 17 minutes to commemorate the 17 students and staff members who were killed in the February 14 massacre. Once the display is over, the shoes will be donated to homeless shelters across the US.
Many Canadian cities have marked the National Day of Remembrance and Action on Violence Against Women on December 6 with similar "shoe memorials". Organizer Emma Ruby-Sachs said she thinks it's a pivotal moment for the movement to end gun violence. Her daughter survived the shooting.
"About five families came that were victims of gun violence", says Oscar Soria, senior campaigner with the protest group.
The Parkers were among the dozens of volunteers at the Capitol calling on Congress to take action. The symbolic shoe demonstrations likely draw inspiration from the renowned memorial at the Hungarian Parliament in Budapest that honors lives lost during the Holocaust.
The memorial comes the day before the scheduled national student walkout to protest gun violence following the Parkland, Florida, high school shooting last month. There has been, on average, at least one school shooting a week in the United States since 2013.