When the Watergate scandal began consuming Nixon's presidency, Martha Mitchell, the notoriously unguarded wife of the attorney general, would call Thomas late at night to unload her frustrations at what she saw as the betrayal of her husband John by the president's men.
It was also during the Nixon administration that the woman who scooped so many others was herself scooped - by the first lady. Pat Nixon was the one who announced to the Washington press corps that Thomas was engaged to Douglas Cornell, chief White House correspondent for UPI's archrival, AP.
They were married in 1971. Cornell died 11 years later.
Thomas stayed with UPI for 57 years, until 2000, when the company was purchased by News World Communications, which was founded by the Rev. Sun Myung Moon, leader of the Unification Church.
At age 79, Thomas was soon hired as a Washington-based columnist for newspaper publisher Hearst Corp.
A self-described liberal, Thomas made no secret of her ill feelings for the final president she covered - the second President Bush. "He is the worst president in all of American history," she told the Daily Breeze of Torrance, Calif.
Thomas also was critical of the U.S.-led invasion of Iraq, asserting that the deaths of innocent people should hang heavily on Bush's conscience.
"We are involved in a war that is becoming more dubious every day," she said in a speech to thousands of students at Brigham Young University in September 2003. "I thought it was wrong to invade a country without any provocation."
Some students walked out of the lecture. She won over others with humorous stories from her "ringside seat" to history.
In March 2005, she confronted Bush with the proposition that "your decision to invade Iraq has caused the deaths of thousands of Americans and Iraqis" and every justification for the attack proved false.
"Why did you really want to go to war?" she demanded.
When Bush began explaining his rationale, she interjected: "They didn't do anything to you, or to our country."
"Excuse me for a second," Bush replied. "They did. The Taliban provided safe haven for al-Qaida. That's where al-Qaida trained."
"I'm talking about Iraq," she said.
Her strong opinions finally ended her career.
After a visit to the White House, David Nesenoff, a rabbi and independent filmmaker, asked Thomas on May 27, 2010, whether she had any comments on Israel. "Tell them to get the hell out of Palestine," she replied. "Remember, these people are occupied and it's their land. It's not Germany, it's not Poland," she continued. Asked where they should go, she answered, "They should go home." When asked where's home, Thomas replied: "Poland, Germany and America and everywhere else."
The resulting controversy brought widespread rejection of her remarks. White House spokesman Robert Gibbs called them "offensive and reprehensible." Many Jews were offended by her suggestion that Israelis should "go home" to Germany, Poland and America because Israel was initially settled in 1948 by Jews who had survived or escaped Hitler's attempt to kill all the Jews in Germany and in neighboring conquered countries.
Within days, she retired from her job at Hearst.
Nicholas F. Benton, the owner and editor of the Falls Church News-Press, approached her about writing again. Benton, who had published Thomas' column for years when she was syndicated, said Thomas was initially dubious about continuing to write for the free weekly paper, which at the time had a circulation around 25,000.
"She said, 'You don't want me. I'm poison," he said in a telephone interview Saturday.
He responded that he could handle any criticism, and her column started running in January 2011. She continued to write about national issues, from Social Security to the State of the Union address and the low capital gains tax, which she blamed for creating "a bigger divide between the haves and the have-nots, leaving not much of a middle class in America."
Benton said some of his advertisers got threatening calls, but he said he received more positive letters than negative ones by "quite a wide margin." And Benton said she continued to be "sharp as a tack," sometimes asking if she could get her column in after deadline because she wanted to monitor some late-breaking development. She wrote for the paper for a year, until her health prevented her from continuing.
"She was just the kind of person who really did want to fight to the finish," he said of her return to writing.
Associated Press writer Jessica Gresko contributed to this report.