First appearance in New and Improved Bartender Manual by Harry Johnson
The Black and Tan name likely originated in England, where consumers have blended different beers since at least the seventeenth century. The tradition of blending beers can be traced to London during the 1700s where beer blends or “three-threads" and “five-threads" were consumed. Each thread was a beer type that was blended into a drink. Three threads was a form of mixed beer alehouses sold to avoid paying a higher tax on beer. By taking a strong beer taxed at a higher rate and mixing it with a small beer taxed at a lower-rate afforded brewers a profit. This practice continued from the late 1690s to 1700s. The earliest recorded usage of the term in the drink context is from 1881, according to the Oxford English Dictionary, in the American magazine Puck. The first recorded British use of the term to describe a drink is from 1889.
However, the name "Black and Tan" is not used in Ireland as a term for a mixture of two beers. The drink is instead referred to as a half and half. In Ireland, the term "black and tan" is associated with the Royal Irish Constabulary Reserve Force, nicknamed the "Black and Tans", which was sent into Ireland in the early 1920s during the Irish War of Independence and resulted in violent outbreaks between the forces and the Irish people.
The Black Nail cocktail was invented sometime between 1947 and 1952. The Black Nail cocktail drink started as a St. Patrick's Day specialty in New York after Desmond E. Williams invented Irish Mist a brown whiskey liqueur in 1947.