When President Barack Obama took the oath of office, it wasn't the first time he addressed the public on inauguration day. That happened hours earlier -- on Twitter.
"We had the president himself tweeting several times, even once apparently from church this morning," BuzzFeed Editor-in-Chief Ben Smith said.
Smith says plenty of other politicians were tweeting as well.
In fact, cellular networks strained under the weight of all these tweeting spectators.
Twitter counted 1.1 million tweets about the inauguration during the ceremony, reaching a peak when the president said, "We cannot mistake absolutism for principle, or substitute spectacle for politics, or treat name-calling as reasoned debate."
But the day's most-tweeted moment was Beyoncé. There were 32,000 tweets per minute while she sang the national anthem.
The armed forces had their own app that let spectators track specific military units through the parade in real time.
"This is the first time we've had phone apps available to the public and a lot of people are getting the opportunity to learn a little bit more about the military's role in the inauguration," Navy Chief Mass Communications Specialist Elizabeth Thompson said.
It's technology evolving so fast, even experts can't keep up.
"We who are using Twitter are kind of the oldsters. If you talk to teenagers, they're using Snapchat, they're using Instagram," Smith said.
The apps keep changing, but Smith says social networks have secured their place in the chronicling of American history.