In observance of the 10-year anniversary of the 9/11 attacks, millions participated in the single-largest day of charitable service in American history. At least 24 major cities held large-scale volunteer service projects, each involving from 1,000 to 10,000 volunteers.

For months, celebrities like Samuel Jackson, Ali Larter, Mariska Hargitay and Jordin Sparks, among others, have been participating in the “I Will” Pay Tribute campaign. They did this by making public service announcements, encouraging Americans to pay tribute on the 10-year anniversary of 9/11 by engaging in good deeds, supporting charitable causes, or volunteering in their communities.

Spearheaded by the nonprofit organization MyGoodDeed, which was the first group to formally call for Sept. 11 to be designated as a federally recognized day of service and remembrance, this globally acknowledged event has raised public awareness through their partnerships with entertainers, survivors and victim’s families. Also essential to the development of the campaign was HandsOn Network, the volunteer activation division of Points of Light Institute, which is the largest volunteer network in the nation.

Entertainers Lady Gaga, Fran Drescher, Pauly D, Nas, Julianne Hough and Drake Bell appear in the newest PSAs created collaboratively by Viacom in support of the 9/11 day of observance. Champion NASCAR drivers Jimmie Johnson and Tony Stewart also appear in another new PSA spot produced by The NASCAR Foundation, which first aired at the NASCAR Sprint Cup Series race at Richmond International Raceway on Sept. 10.

By utilizing public figures to raise awareness, MyGoodDeed and HandsOn Network effectively reached audiences that perhaps wouldn’t have taken the time to stop and think about the impact that 9/11 has had on our country. They aimed to bring about a moment of national unity when differences and competitive concerns should be put aside for the day to honor and rekindle the remarkable spirit of unity shared by so many immediately following the attacks in 2001.

Creating the single-largest day of charitable service in U.S. history was no easy task, but with the help of these celebrities donating their time and energy to create video tributes and PSAs, a strong buzz was created around the event.

Millions of Americans logged on to 911day.org to upload videos, photos, and fill out the 9/11 tribute card describing the good deeds and charitable activities planned to honor the 9/11 victims, survivors and those who rose in service by responding to the attacks.

Through a unique “Service in Memory” feature, the tributes made on the website were then dedicated to individuals lost on 9/11, first responders, recovery workers and members of the military. A companion Facebook page offered a similar functionality.

These uploads are displayed on the site in a “Tribute Quilt,” which collects the videos, photos and tribute pledges in a viewer-friendly “quilt.” This quilt includes the pledges of celebrities as well as everyday citizens aiming to show their remembrance of the tragedy, appreciation for those who sacrificed to help, and volunteering plans for the 9/11 day of tribute.

For more information, visit 911day.org