Riverboat casinos were first legalized in Iowa in 1991 and their popularity has increased dramatically since that time. At first, gambling on riverboat casinos was limited to $5.00 bets and a maximum loss of $200.00 for each cruise passenger. Riverboat casinos gradually moved to Illinois and Mississippi, where there were no limits and casinos were open 24 hours a day. In 1994, riverboat casinos were introduced to Missouri, the last state to legalize riverboat casinos.

Riverboat casinos are legal in six states, Illinois, Iowa, Indiana, Louisiana, Mississippi, and Missouri. They resemble the grand riverboats of the past; however, they seldom leave the shore and remain at dockside. The Mississippi riverboat casinos must be permanently docked, with gangplanks from the shore to the casino. Some riverboat casinos, boats on moats, are large barges with casinos on deck, designed to float on pools adjacent to the river. The majority of the riverboat casinos operate on the Missouri, Ohio, and Mississippi rivers, with the exception of Illinois, which allows them on the Des Plaines, Ohio, and Illinois rivers, as well. Each state has its own gambling restrictions for riverboat casinos, including number allowed, types of games, admission charges, number of hours spent in cruising, and amount of gambling time allowed.

There are a variety of games on riverboat casinos, including blackjack, craps, roulette, poker, slots, and video poker, as well as frequent shows, featured performers, dinner, and dancing. Some popular riverboat casinos include the Argosy VI in Indiana, with 2,300 slots and 80 table games for over 4,000 passengers; the Grand Victoria Casino in Illinois; the Ameristar Casino in Missouri, with the largest floating casino floor in the world; and the Mississippi Belle II in Iowa. The Tunica Queen, a 3-deck riverboat casino featuring afternoon and evening gambling cruises, is very popular in Mississippi. One of the newest riverboat casinos is L'Auberge du Lac in Louisiana, a single-level deck, with 30,000 square feet of gambling space, 60 table games, and 1,600 slot machines. Another well-known riverboat casino in Louisiana is the Treasure Chest, featuring 1,000 slot machines and several types of poker games.

Riverboat casinos add millions of dollars in revenue to the economy of each state, as well as providing employment for thousands. Although natural disasters affect the riverboat casinos each year, gaming developers and individuals contribute to rapid reconstruction and reopening. There remains a bright future for riverboat casinos because of their convenience, reasonable prices, and inexpensive entertainment.