WASHINGTON — An American political consultant whose guilty plea marked the first confirmation that illegal foreign money was used to help fund Donald Trump’s inaugural committee was sentenced to probation Friday by a federal judge who cited his cooperation with U.S. prosecutors.

W. Samuel Patten, 47, in August admitted steering $50,000 from a pro-Russian Ukrainian politician to Trump’s committee in an investigation spun off from special counsel Robert Mueller ‘s probe of Russian interference in the 2016 U.S. election. Patten acknowledged he was helped by a Russian national who is a longtime associate of former Trump campaign chairman Paul Manafort, and the case was referred to prosecutors with the U.S. attorney’s office in Washington and the Justice Department’s national security division.

W. Samuel Patten leaves the federal court in Washington on Aug. 31.  Associated Press/Jose Luis Magana

Before he was sentenced, Patten, accompanied in court by his wife, sister and friends and neighbors, thanked the judge for her handling of his case and asked for a sentence that would permit him to “continue in whatever way I can to serve my country.”

In sparing Patten from prison, U.S. District Judge Amy Berman Jackson accepted prosecutors’ request for leniency and noted no federal sentencing guideline directly applies to his offense of failing to register as a foreign lobbyist, which is punishable by up to five years in prison. Patten’s defense sought probation citing the substantial assistance he provided in several ongoing, undisclosed investigations.

He was sentenced to three years of probation, 500 hours of community service and fined $5,000.

Patten’s offenses were “not a technicality, and not an oversight,” Jackson said in court, but serious offenses calculated to influence public policy and opinion in the United States for a foreign government “without telling the American people that it was those very Ukrainians paying you to do the talking.”

“The whole point, and only point, of the FARA (Foreign Agent Registration Act) statute is to ensure transparency in the public policy and the political process,” Jackson said. “If people don’t have the facts, then democracy doesn’t work.”

Patten “earned the trust of the government and became a reliable and valuable resource” for Mueller’s Russia investigation and prosecutors with the U.S. attorney’s office, Patten’s attorney Stuart Sears said in sentencing papers.

Jackson referred to that assistance, noting Patten did not try to justify or blame his actions on others, “and more importantly, you’ve done everything in your power to make amends” by assisting prosecutors.

“This is not a picture of someone who’s motivated by greed, someone who sells his services to the highest bidder, or someone who’s looking for a cushy or comfortable situation,” Jackson said.

Patten has been released on his own recognizance since pleading guilty Aug. 31.

Without that cooperation in the case, Jackson said she would have considered some prison time for Patten’s lying in the Senate’s Russia probe.

The judge also distinguished his case from Mueller defendant Paul Manafort’s. The former Trump campaign chairman is was given a 7 1/2 year prison term for hiding tens of millions of dollars of income from undisclosed lobbying work for a pro-Russian Ukrainian politician. Manafort’s term includes 30 months Jackson imposed for conspiracy to defraud the United States by abusing FARA and other laws.

“Just to clarify, my prior sentence for Paul Manafort was not” just for conspiring to violate FARA, but also to violate foreign bank account registration requirements,] income tax and money laundering laws, Jackson said.

Assistant U.S. Attorney Fernando Campoamor-Sanchez agreed, saying Patten “really is in a different position [from other FARA cases], we believe in a positive way.”

Patten admitted in court documents that he failed to register with the Justice Department while he worked on behalf of a Russia-aligned Ukrainian political party. Patten acknowledged arranging for an American to act as a “straw donor” to give the $50,000 in exchange for four Trump inauguration tickets for a Ukrainian businessman.

Trump’s inauguration, which raised a record $100 million, was attended by an unusually large number of prominent foreign business leaders, particularly Russian moguls, but foreigners are barred from contributing to the event.

Federal prosecutors in Manhattan, the attorneys general for the District and New Jersey, and the House Intelligence and Judiciary committees have launched separate investigations into the Trump committee and top officials in probes focused on donations and spending.

Sears, noted his client’s past work promoting democracy abroad and promising start as a political consultant. “Without a doubt, Mr. Patten earned his felony conviction in this case, Sears said, but also earned a non-incarceration sentence. “He had a choice to make in this case, between his career and assisting the government. He chose his country . . . He sacrificed his career . . . in order to help the government and cooperate in this case.”

In plea papers, Patten said he formed a company with a Russian national, identified as “Foreigner A,” to engage in lobbying and political consulting services.

The company had received about $1 million since 2015 for its Ukraine consulting work, which included advising a Ukrainian party known as the Opposition Bloc as well as some of its members, one of whom is a prominent Ukrainian business executive identified only as “Foreigner B.”

Prosecutors said Patten helped the business executive get meetings to lobby members of Congress in 2015 and helped him author an op-ed in February 2017 that appears to match a U.S. News & World Report article arguing Ukraine would do fine under President Trump.

The description of “Foreigner A” matches Konstantin Kilimnik, a longtime Manafort associate charged in Washington along with Manafort with obstruction of justice and witness tampering. Prosecutors have said they believe that Kilimnik has ties to Russian intelligence. Kilimnik has denied any such ties, and Patten said he had no idea such links were alleged.

The description of “Foreigner B” matches Serhiy Lovochkin, a Ukrainian business executive and politician who served as a top aide to former Ukrainian president Viktor Yanukovych, a pro-Russian politician who was Manafort’s chief client.

Patten told prosecutors that he worked with Kilimnik to help Lovochkin route the illegal donation to Trump’s inauguration. Prosecutors do not say whether Kilimnik attended.

Patten also agreed that he misled the Senate Intelligence Committee when he testified before the panel in January.

Lovochkin’s office has said he attended the inauguration but did not make the $50,000 payment.

Patten acknowledged to the Senate Intelligence Committee that he falsely minimized his contact with U.S. officials on behalf of foreign clients and manually deleted 200,000 emails from his Gmail archive folder, his attorney said in court filings. But he voluntarily provided materials that incriminated him, including over 1,300 pages of documents, Sears wrote.

Patten initially responded to the committee without receiving a subpoena and without consulting a lawyer, Sears said.

U.S. Attorney General William Barr announced that Mueller concluded his probe March 27 without further indictments, but the special counsel had been referring several matters to other prosecutors, including the U.S. attorney’s office for the District.

Patten worked in the oil sector in Kazakhstan in the mid- to late 1990s and served as Maine campaign director for George W. Bush’s 2000 presidential run. He also briefly worked at the State Department under Bush and as a political consultant in Iraq assisting officials there in the post-Saddam Hussein period.

In a 2017 interview with The Post, Patten said he met Kilimnik in Moscow more than 15 years ago, when Kilimnik was an employee of the International Republican Institute, a pro-democracy group affiliated with the U.S. Republican Party. Patten ran the office from 2001 to 2004. “I relied on him,” Patten said in the interview.

Kilimnik left the IRI around 2005 to work for Manafort in Kiev, the Ukrainian capital, eventually being named manager of Manafort’s Ukraine office. Patten praised Kilimnik at the time as a person who helped Manafort navigate the complicated Ukrainian political scene.

Lovochkin’s office has said he attended the inauguration but did not make the $50,000 payment.

Patten acknowledged to the Senate Intelligence Committee that he falsely minimized his contact with U.S. officials on behalf of foreign clients and manually deleted 200,000 emails from his Gmail archive folder, his attorney said in court filings. But he voluntarily provided materials that incriminated him, including over 1,300 pages of documents, Sears wrote.

Patten initially responded to the committee without receiving a subpoena and without consulting a lawyer, Sears said.

U.S. Attorney General William P. Barr announced that Mueller concluded his probe March 27 without further indictments, but the special counsel had been referring several matters to other prosecutors, including the U.S. attorney’s office for the District.

Patten worked in the oil sector in Kazakhstan in the mid- to late 1990s and served as Maine campaign director for George W. Bush’s 2000 presidential run. He also briefly worked at the State Department under Bush and as a political consultant in Iraq assisting officials there in the post-Saddam Hussein period.

In a 2017 interview with The Post, Patten said he met Kilimnik in Moscow more than 15 years ago, when Kilimnik was an employee of the International Republican Institute, a pro-democracy group affiliated with the U.S. Republican Party. Patten ran the office from 2001 to 2004. “I relied on him,” Patten said in the interview.

Kilimnik left the IRI around 2005 to work for Manafort in Kiev, the Ukrainian capital, eventually being named manager of Manafort’s Ukraine office. Patten praised Kilimnik at the time as a person who helped Manafort navigate the complicated Ukrainian political scene.