Robert Thompson, a Syracuse University professor and an expert on popular culture, said the internet also reflects the current division in the US.

"Safe to say, if what happened on Sept 11 happened today, the response would have been vastly different. The major variable is social media and the explosion of the digital environment," he said.

"Instead, a 'we're all in this together' narrative took hold in the media in the aftermath of the terrorist attacks and remained there until the Bush administration began pushing to invade Iraq, which happened in March 2003.

"We had Jay Leno vowing not to make fun of the way (former) president George W. Bush mispronounces words. There is no way that warm, unified feeling would happen today."

Back then, there was no Facebook, no Twitter, no Reddit or other social media platform. However, on the 20th anniversary of the terrorist attacks, Americans took to the platforms to share messages of mourning and resilience in memory of the nearly 3,000 victims.

"It's like everything had changed, but nothing had changed. We all grew up a bit more that day. I no longer felt as safe as before 9/11. It was like I finally realized how much we were really connected to the rest of the world," wrote netizen txmartini01 on social media.