Special Counsel Robert Mueller's investigation into possible collusion between Russia and the Trump campaign concluded in late March. Attorney General William Barr publicly revealed the "principal conclusions" and more about the under-wraps investigation in a 448-page “limited” redacted document weeks later.

Just months after President Trump was inaugurated into office, Mueller was appointed to the special counsel's office on May, 17 2017. In total, it lasted close to two years — 675 days, or one year, 10 months and six days, to be exact.

READ THE MUELLER REPORT FINDINGS

The intent of the investigation was to determine whether Trump and his campaign illegally worked with Russia to sway the 2016 presidential election. The special counsel's office determined that it "did not find that the Trump campaign or anyone associated with it conspired or coordinated with Russia."

In total, 19 attorneys worked with the special counsel's office at some point during the nearly two-year-long probe, which, between May 2017 and September 2018, spent $25.2 million. Of that, $12.3 million was direct spending, while $12.9 million was spent on "indirect" component expenses for the Justice Department.

The special counsel's office has said that the indirect expenses don't amount to additional taxpayer expenditures since those resources — especially personnel, such as employees of the FBI or other agencies — would have been devoted to other cases had there been no special-counsel investigation.

During the investigation, at least 42 people were interviewed by Mueller or his team or testified before a grand jury, and 34 people — in addition to 3 companies — either have been indicted or have pleaded guilty in connection to the probe.

Of the 34, 6 were former advisers or associates of Trump, while 2 were not considered Trump advisers or associates. Additionally, 26 Russians have been charged.

Mueller's office worked with a team of "approximately 40 FBI agents, intelligence analysts, forensic accountants, and other professional staff" during the investigation.

CLICK HERE TO GET THE FOX NEWS APP

Ultimately, the special counsel's office "issued more than 2,800 subpoenas, executed nearly 500 search warrants, obtained more than 230 orders for communication records, issued almost 50 orders authorizing use of pen registers, made 13 requests to foreign governments for evidence, and interviewed approximately 500 witnesses," according to Barr's letter.