WASHINGTON, D.C.–An estimated 800,000 to 1 million people packed the National Mall outside the U.S. Capitol on Monday to witness the public swearing-in of the nation’s first Black president, Barack Obama.

“I had to be here to see this for myself–I’m not going to see this again in my lifetime,” said Carley Williams, a Philadelphian who was in the golden-ticketed section of the Mall and explained that the opportunity to see a Black president sworn in may “unfortunately” be her last.

This year’s inauguration saw less of a turnout than Obama’s first, in which an estimated 1.8 million packed the Mall. While bird’s-eye photos of this year’s crowd showed hundreds of thousands of people waving American flags, blending into a sea of purple (mixed red and blue), the atmosphere on the ground was more restrained than in 2009. It seemed the 2013 crowd was more politically minded, intently listening to, reflecting on and then discussing

the political speeches of the day rather than simply partying and celebrating the inauguration as they did in 2009.

“This year is not only about making history,” said one young man on the Mall. “I mean, I’m here to witness history, obviously, but it’s about accountability, too.”

This year there was also a new way to tell just what Americans were thinking regarding the inaugural speeches and the day’s events. While wireless service on the Mall was spotty, social media played a much bigger role among the participants at this year’s inaugural events.

Instagram, which was not launched until 2010 and thus was not around for Obama’s first inauguration, saw hundreds of thousands of photos posted about the inauguration. CNN, which used the Instagram hashtag #cnn for inaugural events, reported receiving over 10,000 photos on the social media site about the occasion.

“I’m home reading the Washington Post and stopped at this picture in awe that I lived during a time such as this. I’m so incredibly grateful to have witnessed this event on the Capitol lawn #inauguration2013 #obama #mrpresident #greatmen #strongmen #integritymen #electedtwoterms #usa #barackhobama #president #twoterms #2ndact,” read one Instagram photo posted by vbridgefor, showing the diversity of tagging that was used during the day.

Foursquare, which partnered with the presidential inauguration committee, offered a special Inaugural Service badge for those who participated in inaugural events and saw over 30,000 people check in to the inauguration on the phone app.

Some joked that Michelle Obama “broke Twitter” when she emerged in her red Jason Wu dress at the inaugural ball on Monday night, and Twitter, which did report on Monday that it was experiencing service problems, still tallied 1.1 million inauguration-related messages, reaching up to 27,795 tweets per minute, during the inauguration ceremony–a time period of only about one hour. At Obama’s last inauguration, Twitter reported a maximum of only about 3,000 tweets per minute.

On Facebook, Beyonce actually stole the inaugural show, beating out the president and the word “inauguration” in mentions for the day. According to the U.S. politics Facebook team, Facebook saw a 42,450 percent spike in mentions of Beyonce at 12:30 p.m. on Monday, around the time that the pop singer performed the national anthem. Mentions of President Obama peaked at a mere rise of 3,375 percent at 11:52 a.m. on Monday.

The Obamas’ daughters, Malia and Sasha, also went viral after the tweens were photographed dancing and taking selfies (photos of themselves) during the day’s events.

While Americans watched, photographed, tweeted, posted and talked about the historic significance of Monday’s events, another person turned around and looked back at them.

Just before walking off the inauguration stage, Obama was caught by news cameras turning around to look at the sprawling crowd. “I want to take a look one more time,” Obama said. “I’m not going to see this again.”