The first presidential debate was the most watched in American history

The presidential debate between Donald Trump and Hillary Clinton Monday night drew well over 80 million viewers, and was the most-watched in the history of televised debates.

The Nielsen data is still being counted, and the final tally will be released later today. But so far, the numbers are pretty huge. There were 80.9 million viewers who tuned in across 12 television channels, according to preliminary ratings reported by CNN.

SEE ALSO: CNN said Hillary won the debate. Why do online polls say otherwise

The last time ratings for a TV presidential debate came even close to that was over 35 years ago, when 80.6 million tuned into the debate between Jimmy Carter and Ronald Reagan, according to trade publication Adweek.

This week's numbers don't even include people who may have watched the debate from places like bars, restaurants, offices and so forth. Traditionally, the Nielsen ratings only include people who watch television from home, according to CNN. The record 80 million viewers also doesn't include PBS and C-SPAN.

Viewers were also able to watch the debate on the live streams of several Youtube channels from news outlets like The Washington Post, Fox News and Telemundo. ABC News and Facebook teamed up to do a stream, and so did Twitter and Bloomberg.

This Tweet is currently unavailable. It might be loading or has been removed.

The debate was also the most tweeted ever, Twitter confirmed to Mashable Monday.

The site is still crunching the numbers but they are higher than the 10.3 million tweets sent out during a 2012 presidential debate.

UPDATE: Sept. 27 1:13 p.m. PT: Nielsen says 81.4 million watched the debate on 11 networks, according to preliminary estimates.

This Tweet is currently unavailable. It might be loading or has been removed.