He was the third of five children:
- Harold Nixon (June 1, 1909 – March 7, 1933)
- Richard Nixon (January 9, 1913 – April 22, 1994)
- Donald Nixon
- Arthur Nixon (May 26, 1918 – August 10, 1925)
- Edward Nixon (May 3, 1930)
In January 1957 Howard Hughes lent Donald Nixon $205,000 to bail out his "Nixon's" drive-in restaurant in Whittier, California. The restaurant went bankrupt less than a year later. Questions about whether this was a political favor dogged Richard Nixon during his campaign for president and later when he sought the governorship of California.
He never lived it down and one of the many speculated motives for the 1972 Watergate burglary that ultimately led to Richard Nixon's resignation was a desire to find proof that the then-Democratic National Committee chairman Larry O'Brien was also secretly working for Hughes. John H. Meier, one of Hughes's former business advisers, in collaboration with former Vice President Hubert Humphrey and others, was using Donald Nixon to feed misinformation to his brother the President. Meier told Donald that he was sure the Democrats would win the election since they had a lot of information on Richard Nixon's illicit dealings with Howard Hughes that had never been released, and that Larry O'Brien had the information (O'Brien didn't actually have any documents but Meier wanted Richard Nixon to think he did). Donald then called his brother and told him that Meier gave the Democrats all the Hughes information that could destroy him (Richard Nixon) and that O'Brien has it.
In 1973, financier Robert Vesco fled the United States hoping to avoid prosecution on charges of embezzlement. Shortly before his departure, in hopes of shutting off the United States Securities and Exchange Commission investigation into his activities, Vesco routed substantial political contributions to President Richard Nixon through the president's nephew, Donald Nixon Jr.
In 1974 the staff of the Senate Watergate committee disclosed additional information to support the charge that Charles Rebozo gave or lent part of a $100,000 campaign contribution to President Nixon's personal secretary, Rose Mary Woods, and to Nixon's brothers, Donald and Edward Nixon.
- DuBois, Larry, and Laurence Gonzales (September 1976). The Puppet and the Puppetmasters. Playboy
- Stern, Carl (April 10, 1974). Vanderbilt Television News Archive: Howard Hughes Contribution / Kalmbach Version. NBC Evening News
- Haldeman, H.R. and Joseph Dimona (1978). The Ends of Power. Dell: ISBN 0-440-12239-2
- "Hughes Nixon and the C.I.A.", Playboy magazine, September 1976
- Age of Secrets: The Conspiracy that Toppled Richard Nixon and the Hidden Death of Howard Hughes written by Gerald Bellett, 1995, Voyageur North America, ISBN 0-921842-42-2
- Crewdson, John M. (July 11, 1974). Report Questions Rebozo's Account on Hughes Funds. New York Times
- Nixon Fun Facts via Nixon Foundation