Henry Chadwick was born October 5, 1824 in Jessame Cottege, St. Thomas, Exeter, England. He was the son of Sir James Chadwick, a newspaper editor. Henry and his parents immigrated to the United States in September 1837 and settled in Brooklyn. Henry studied to be a music teacher, but pursued a career in journalism. Throughout his life Chadwick wrote for more than twenty magazines and newspapers. He married Jane Botts on August 19, 1848, with whom he had two children.

As a child, Chadwick was exposed to the game of baseball, although he much preferred the more refined game of cricket. Chadwick first took serious interest in baseball in 1856, when he witnessed a well-played game between two of New York’s most notable baseball clubs: the Eagle and Gotham Clubs. While witnessing that particular game, Chadwick realized baseball was "just the game for a national sport for Americans." By 1860, Chadwick dedicated his career to advocating the development of baseball as a sport, and expanding the visibility of baseball in the press.

As member of the rules committee of the National Association of Base Ball Players, Chadwick wrote the first rules book in 1859 and the Beadle’s Dime Base Ball Player in 1860, baseball’s first annual reference guide. He published several other works about baseball and edited Spalding’s Official Base Ball Guide from 1881 to 1908. Through his writings, Chadwick attempted to portray baseball as a serious sport, and was thus instrumental in developing methods to describe baseball performance with statistics.

Chadwick recognized and welcomed the prospect of baseball becoming a profession. He strongly opposed corruption and led a campaign to rid baseball of gambling, betting, bribery, and fixed outcomes. Although Chadwick believed baseball suited the American National character, he objected to the belief of many observers, Albert G. Spalding included, that baseball was an American invention. Chadwick argued that baseball was derived from the English schoolyard game Rounders.

Nevertheless, Chadwick remained dedicated to bringing baseball to the forefront of American leisure activities and was recognized for his contribution to the baseball establishment. He was elected the first vice president of the Base Ball Reporters Association of America in 1887, was made an honorary member of the National League in 1894, and in 1904 became the only journalist to have been awarded a medal from the St. Louis World’s Fair. In 1908, Chadwick caught a cold while attending opening day and subsequently died of pneumonia a few days later on April 20. In 1938, Chadwick became the only sportswriter elected to the National Baseball Hall of Fame, and remained the only sportswriter so honored until the establishment of the annual J. G. Taylor Spunk Award in 1962.