Short answers, pulled from the story.
James Baker served as the 10th White House chief of staff under President Ronald Reagan from 1981 to 1985, then as the 67th secretary of the treasury from 1985 to 1988. Under President George H.W. Bush, he served as the 61st secretary of state from 1989 to 1992, and then returned as the 16th White House chief of staff in 1992 to 1993.
The Plaza Accord was a September 1985 agreement among the finance ministers of the United States, Japan, France, West Germany, and the United Kingdom, reached at the Plaza Hotel in New York City. Baker, as secretary of the treasury, convened the meeting and negotiated an agreement for the parties to sell American currency holdings to engineer a 10-12 percent depreciation in the dollar. Baker kept most of the Reagan administration out of the loop to prevent speculation.
Baker made statements in mid-October 1987 suggesting the U.S. would not defend the dollar against the Deutsche mark, which the New York Times of the 18th of October 1987 described as an "abrupt shift" that might "erode markets." The following day, the Dow Jones Industrial Average fell 22.6 percent. However, the Brady Commission investigation assigned Baker only a peripheral role, finding that computer technology, group psychology, and somewhat inflated stock valuations were equally or more responsible.
During German reunification negotiations, Baker told Soviet Foreign Minister Eduard Shevardnadze and Premier Mikhail Gorbachev that "there would be no extension of NATO's jurisdiction for forces of NATO one inch to the east." Vladimir Putin later cited this statement to justify Russia's 2014 annexation of Crimea, but Gorbachev explicitly rejected that interpretation and dated NATO's eastward expansion to 1993.
Baker managed George W. Bush's legal team during the Florida presidential recount. His team numbered around 30 people, many from his law firm Baker Botts, and included lawyers later appointed to government positions by the Bush administration: John Bolton, John Roberts, Brett Kavanaugh, and Amy Coney Barrett. Baker was the first person to congratulate Bush as president-elect after the Supreme Court's opinion was faxed to campaign headquarters.
Baker gave a commencement address at Rice University in 1991, which prompted political science professor Richard Stoll to suggest Baker as a candidate for a public policy institute should Bush lose re-election. The announcement came on the 14th of January 1993. The connection also had deep family roots: Baker's grandfather was the personal lawyer for William Marsh Rice, the university's namesake, chaired the Board of Trustees from its 1891 charter until 1941, and was himself the namesake for Baker College, Rice's first residential college.