A private trust was created by the Irish government in 1930 to run this granddaddy of all lotteries, the proceeds from which benefitted Irish hospitals. Tickets were sold throughout the world, even in places where such activities were sometimes banned.
The purchaser of a ticket got half, the other half was returned to Ireland. All stubs were placed in a large barrel, from which some number were drawn. Each stub drawn won a cash prize. In addition, each winning stub was matched to the name of a horse running in a major Irish or British horse race. Large prizes went to ticket holders whose horses managed to win, place or show in their race.
The Irish Sweepstakes was the first 'modern' lottery, and established a pattern for those that followed. They actually ended in 1987, replaced by an Irish state lottery programme.
My grandfather held a winning ticket in the 1937 Sweepstakes. The prize for the ticket itself was $1920, and his ticket was matched with a horse named "Epigram," the favorite in a upcoming horse race (perhaps in England, we don't have details). Grandfather stood to win $148,000 if Epigram won, $74,000 for place and $48,000 for show. He was soon approached by a New York syndicate who wanted to buy the ticket from him for $14,600. He agreed to sell them a half-share in the ticket, and received $7300 in hundred dollar bills. This reduced his possible winnings by 50%, but gave him 73 crisp hundred dollar bills, which went right into the bank. Or so he told newspaper reporters, anyway.
As it happened, Epigram finished out of the money, leaving Grandfather a bit disappointed but happy to have covered his bet with the half-share sale. Grandfather, who was an auctioneer by trade but dabbled in horse trading on the side, undoubtedly put the money to use in other horse racing activities.