Special counsel Robert Mueller's investigation into Russia's attempts to interfere in the 2016 presidential election took two years to complete.

The long wait to read Mueller's voluminous report is over, with U.S. Attorney General William Barr releasing a redacted version Thursday — first to members of Congress, then the American public.

Here are five things you should know about Mueller's report and Barr's presentation of it:

1.) Russia did try to interfere with the 2016 election

Barr, at a Thursday morning news conference ahead of the report's release, said Russia worked to "illegally interfere" in the 2016 presidential election. He said he found that extremely concerning, a belief he said he shared with all Americans. The Russians' goal, according to published reports, was to harm Hillary Clinton's campaign.

2.) Barr says no collusion, no obstruction of justice by Trump

Barr, in a four-page letter summarizing the report, told members of Congress that Mueller found no evidence President Donald Trump colluded with the Russians. Barr also said he believes there was no credible evidence that Trump acted in a manner that could be interpreted as obstruction of justice.

3.) Trump claims vindication

President Trump, who has claimed innocence throughout the entire investigation, was quick Thursday morning to take to Twitter, posting, among other things, "No Collusion - No Obstruction!" Another Tweet directed at "the haters and the radical left Democrats" simply said, "Game over."


— Donald J. Trump (@realDonaldTrump)April 18, 2019

4.) Redactions required by law

While many have been clamoring for a full version of the Mueller report, Barr said that's not possible because of several exemptions spelled out in U.S. law. Some redactions, for instance, were required because they dealt with grand jury proceedings. The attorney general characterized the redactions as minor in nature and said Americans would still be able to get the gist of what Mueller discovered.

5.) Investigation cost millions

The cost of the entire two-year investigation is not yet known, but Time magazine estimates taxpayers spent in excess of $25 million to fund Mueller and his team.

By contrast, the Regan administration Iran-Contra probe cost about $94 million, adjusted for inflation, and the Clinton-era investigations by Kenneth Starr cost more than $100 million in today's dollars.