Short answers, pulled from the story.
Nixon resigned on the 9th of August, 1974, facing almost certain impeachment and removal from office as a result of the Watergate scandal. The scandal began with a break-in at the Democratic National Committee offices ordered by administration officials and escalated despite cover-up efforts by the Nixon administration, of which Nixon was aware.
The Checkers speech was a televised address Nixon gave on the 23rd of September, 1952, to defend himself against allegations that a political fund maintained by his backers created a conflict of interest. About 60 million Americans watched or heard it, the largest audience ever for a television broadcast at that point. Nixon acknowledged receiving a cocker spaniel dog named Checkers as a gift, which he said he would not return.
Nixon visited China in February 1972, the first sitting U.S. president to do so, after clandestine groundwork by National Security Advisor Henry Kissinger. The visit ushered in a new era of U.S.-China relations; the joint communique recognized Taiwan as part of China and looked forward to peaceful reunification.
In August 1971, Nixon ended the direct international convertibility of the U.S. dollar to gold, effectively taking the United States off the gold standard. This decision led to the collapse of the Bretton Woods international monetary system.
Nixon defeated Democratic Vice President Hubert Humphrey and American Independent Party candidate George Wallace in 1968, winning 301 electoral votes to Humphrey's 191 and Wallace's 46. His margin in the popular vote was only about 500,000 votes, a gap of less than one percentage point.
Nixon announced the formation of the Environmental Protection Agency in June 1970 and signed the Clean Air Act of 1970, the Endangered Species Act, and the National Environmental Policy Act, which required environmental impact statements for many federal projects. He also signed into law the Occupational Safety and Health Administration.