Title: History of Las Vegas
Content:  reluctantly became the last western state to outlaw gambling. This occurred at midnight, October 1, 1910, when a strict anti-gambling law became effective in Nevada. It even forbade the western custom of flipping a coin for the price of a drink. Nonetheless, Las Vegas had a diversified economy and a stable and prosperous business community, and therefore continued to grow until 1917. In that year, a combination of economic influences and the redirection of resources by the federal government in support of the war effort forced the Las Vegas and Tonopah Railroad to declare bankruptcy. Although William Clark sold the remains of the company to the Union Pacific Railroad, a nationwide strike in 1922 left Las Vegas in a desperate state.
Title: History of Nevada
Content:  Las Vegas on the map by first building the most expensive casino in the world, the Flamingo, and then by being gunned down in his Beverly Hills home. Las Vegas casinos of the 1950s were mostly low-rise building taking advantage of the wide-open spaces that Reno didn't offer in the downtown area of Virginia Street. However, Las Vegas boomed with new luxurious hotels in the 1960s and the city's gambling casinos drew players from all over the world, and away from Reno and Lake Tahoe. Gambling is what Nevada is famous for. The 1931 gambling law enabled the explosive growth of the Las Vegas area, where the population grew from 5 thousand in 1930 to 1.9 million in 2008.
Title: History of Las Vegas
Content:  the local level in 1931. Las Vegas, with a small but already well-established illegal gambling industry, was poised to begin its rise as the gaming capital of the world. The county issued the first gambling license in 1931 to the Northern Club, and soon other casinos were licensed on Fremont Street, such as the Las Vegas Club and the Hotel Apache. Fremont Street became the first paved street in Las Vegas and received the city's first traffic light in 1931. In reply, the federal government restricted movement of the dam workers to Las Vegas. Smuggling and circuitous routes then were developed. In 
Title: Las Vegas
Content:  City and Los Angeles, where they would travel to gather supplies. The fort was abandoned several years afterward. The remainder of this Old Mormon Fort can still be seen at the intersection of Las Vegas Boulevard and Washington Avenue. Las Vegas was founded as a city in 1905, when 110 acre of land adjacent to the Union Pacific Railroad tracks were auctioned in what would become the downtown area. In 1911, Las Vegas was incorporated as a city. 1931 was a pivotal year for Las Vegas. At that time, Nevada legalized casino gambling and reduced residency requirements for divorce to six weeks. This year also witnessed the beginning of construction on 
Title: Downtown Las Vegas
Content:  Las Vegas was founded as a city in 1905, when 110 acres of land adjacent to the Union Pacific Railroad tracks were auctioned in what would become the downtown area. The first hotel in the area, the Hotel Nevada, was built in 1906; it is still operating as the Golden Gate Hotel and Casino. In 1911, Las Vegas was incorporated as a city. The year 1931 was a pivotal one for Las Vegas. At that time, Nevada legalized casino gambling and reduced residency requirements for divorce to six weeks. This year also witnessed the beginning of construction on nearby Hoover Dam. The influx of construction workers 
Title: Las Vegas, New Mexico
Content:  Las Vegas was established in 1835 after a group of settlers received a land grant from the Mexican government. The town was laid out in the traditional Spanish Colonial style, with a central plaza surrounded by buildings which could serve as fortifications in case of attack. Las Vegas soon prospered as a stop on the Santa Fe Trail. During the Mexican–American War in 1846, Stephen W. Kearny delivered an address at the Plaza of Las Vegas claiming New Mexico for the United States. In 1847, the town was the site of the Battle of Las Vegas, which was a part of the broader Taos Revolt by local Hispanos 
Title: History of gambling in the United States
Content:  To overcome the Great Depression, Nevada legalised gambling as a way to bring economic relief. In 1931, Nevada legalised most forms of gambling when Assembly Bill 98 was signed into law, providing a source of revenue for the state. Interest in development in the state was slow at first, as the state itself had a limited population. After 1945, enforcement of gambling laws became more strict in most places and the resort town of Las Vegas became an attractive target for investment by crime figures such as New York's Bugsy Siegel. The town rapidly developed during the 1950s, dooming some 
Title: History of Las Vegas
Content:  The settlement of Las Vegas, Nevada was founded in 1905 after the opening of a railroad that linked Los Angeles and Salt Lake City. The stopover attracted some farmers (mostly from Utah) to the area, and fresh water was piped in to the settlement. In 1911, the town was incorporated as part of the newly founded Clark County. Urbanization took off in 1931 when work started on the Boulder Dam (now the Hoover Dam), bringing a huge influx of young male workers, for whom theaters and casinos were built, largely by the Mafia. Electricity from the dam also enabled the building of many new hotels along the Strip. The arrival 
Title: Timeline of Las Vegas
Content:  "conservative city government". ; 1920 ; Population: 2,304. ; 1930 ; Population: 5,165. ; 1931 ; Gambling legalized. ; Hoover Dam construction begins near Las Vegas. ; 1933 ; Post Office built. ; 1934 ; Helldorado festival begins. ; 1940 ; Population: 8,422. ; Las Vegas Union Pacific Station built. ; 1941 ; Las Vegas Army Airfield activated. ; 1943 ; Las Vegas YMCA active. ; 1944 ; Huntridge Theatre built. ; 1946 ; Flamingo Hotel and Golden Nugget casino in business. ; 1950 ; Population: 24,624. ; U.S. military Nellis Air Force Base dedicated. ; Las Vegas Morning Sun newspaper begins publication. ; 
Title: Las Vegas in the 1940s
Content:  Las Vegas in the 1940s was notable for the establishment of The Strip in a town which "combined Wild West frontier friendliness with glamor and excitement". In 1940, the population was 8,400 but within five years, it more than doubled its size. The Las Vegas Valley had a population of 13,937 in 1940, increasing to 35,000 in just two years.

Question: when did las vegas become a gambling town?
Answer: 1931.
In 1931.