In his career at The Guardian newspaper, Winchester covered numerous significant events, including Bloody Sunday and the Watergate Scandal.

[9][10][11] After leaving Northern Ireland in 1972, Winchester was briefly assigned to Calcutta before becoming correspondent for The Guardian in Washington, DC, where he covered news ranging from the end of Richard Nixon's administration[12] to the start of Jimmy Carter's presidency.

[4] In 1982, while working as chief foreign feature writer for The Sunday Times, Winchester was on location for the invasion of the Falkland Islands by Argentine forces.

The Map that Changed the World (2001) focuses on the geologist William Smith and was Winchester's second New York Times best seller.

[17] The year 2003 saw the publication of The Meaning of Everything, which returns to the topic of the creation of the Oxford English Dictionary, and of the best-selling Krakatoa: The Day the World Exploded.

He managed to step on shore briefly before being escorted away, and was told by British authorities: “Go away and don’t come back.”[22] On 4 July 2011 Winchester was naturalized as an American citizen in a ceremony aboard the USS Constitution.

[23] He is the founder, editor and reporter of the Sandisfield Times, a hyper-local newspaper focused on issues in the small Berkshires town.