Chinatown is a location that has been an important part of Vancouver's history since it was founded in 1886. I could find very little information about the arch itself, other than a photo from 1901 of an arch at this spot that predates the one seen today.
However, I did find a great history of the history of the Chinese citizens of Vancouver that was very interesting and that I'll post here. The text is from the Chinatown Neighborhoods Website:
The Chinese in British Columbia are usually thought of as immigrants, but many were pioneers as well. Years before Vancouver was incorporated in 1886, Chinese labourers worked in the industries that built the province -- in gold fields, coalmines, sawmills and canneries. Many emigrated from southern China, where English-speaking Chinese bosses recruited them to work under contract in Canada. Between 1881 and 1885, for example, 10,000 Chinese were contracted to build the Canadian Pacific Railway. And in 1882, the United States passed a law barring Chinese CPR labourers. Out of work and with little money, many came to Vancouver.
Many Chinese labourers lived in Chinatown only between jobs. Often they were out of Vancouver for months at a time working at seasonal jobs, like lumbering or canning fish. In Chinatown, they usually lived in crowded rooming houses in the Pender Street area. Some of them turned to opium for solace; others gambled. These activities frightened and fascinated white Vancouver, which both launched campaigns to close down the Chinatown "vice dens" and privately patronized them.
Not all the Chinese shared the circumscribed life of the labourers. Class distinctions in Chinatown were sharp. At the top were a handful of wealthy firms run by individuals who controlled much of the business life of Chinatown. The firms grew rich contracting workers, importing and exporting, investing in real estate, selling steamship tickets and manufacturing opium (which was legal to manufacture for export). Partners in the wealthiest firms lived in Chinatown in great luxury and elegance surrounded by their family members.
More numerous were the middle-class merchants, who owned and operated green-groceries, laundries, tailor shops and other small businesses. Often they chose these occupations for lack of other options—for instance, civic politicians barred them from employment on City works!
The Chinese created their own associations to aid their fellows. Associations based on common surnames or place of birth in China provided social activities and social services in Chinatown. Members raised funds to build the imposing headquarters that still line Pender Street. Some also sponsored rotating credit associations, a kind of lottery among friends, which provided the capital for many new Chinatown businesses.
During Vancouver's prosperous years between 1897 and 1913, Chinatown grew as Chinese merchants invested in new properties. They extended Chinatown south along Carrall Street, west to Shanghai Alley and Canton Alley, and eventually east along Pender Street to Gore Street.
But even the wealthiest Chinese lived on the margins of Vancouver society. Discrimination took many forms, from disparaging cartoons in local newspapers to systematic harassment by City inspectors. The Chinese were not allowed to vote in city, provincial or federal elections. Powerless at the ballot box, they nevertheless actively resisted discriminatory measures. Chinese people frequently took the City to court to redress their grievances. Chinatown itself was a response to the climate of racial hostility. The Chinese were not legally required to live apart from white folk, but the "unfriendly feelings" in the rest of the city made it seem the wiser course.
In bad times, when jobs were scarce, anti-Chinese sentiment peaked. Union workers resented Chinese labourers because they were often used by employers to break strikes. Chinese labour bosses prevented contact between Chinese workers and the organized union movement, hoping to maintain their supply of cheap labour.
In 1907 the boom that began with the Klondike Gold Rush of 1897 faltered. The mild recession focused attention on Chinese workers. That year Vancouver's Asiatic Exclusion League held a rally attended by thousands. Afterwards, a mob marched on Chinatown, smashing property and looting stores. After World War I, another job shortage led to renewed calls to restrict Chinese immigration. In 1923 the Federal Government responded by passing the Exclusion Act, which effectively barred all new Chinese immigration. Until its repeal 25 years later, Vancouver's Chinatown commemorated its passage with an annual Humiliation Day.
Under the Exclusion Act, Chinatown stagnated. The community of aging men and women was unable to grow without new immigration. During the 1930s the Vancouver Chinese community lost 6,000 people, half of its members, by death or emigration. The Depression hurt Chinatown too. The City legislated lower levels of relief for Chinese than for white residents. In all, 175 patrons of Chinatown's Pender Street soup kitchen died of malnutrition during those years.
World War II brought dramatic change to the status of the Chinese and Chinatown in Vancouver. During the war, China fought as Canada's ally, and the war taught a powerful lesson about the folly of racism. In 1947 the Canadian Government repealed the Exclusion Act. Finally, ordinary Chinese were able to bring their wives and children from China. Chinatown, always crowded, could not contain the newcomers. Many families found homes in the old working-class neighbourhood of Strathcona, immediately east of Chinatown.
During the war and afterwards, Vancouver began to look at Chinatown in a new way. Suddenly the Chinatown that had seemed foreign, sinister and dangerous began to seem foreign, exotic and appealing. From all over the city, residents traveled there with the enthusiasm of tourists—sampling foods, buying curios and savoring the district's distinctiveness. Merchants and restaurateurs added glamour to Chinatown's new image with glittering new neon signs.
In the 1960s, Vancouver planned its first major freeway to cut right through Chinatown. But in 1968 citizens' action groups effectively intervened, and caused the plan to be abandoned. The Province also recognized Chinatown's special history and architecture by designating it a historic district in 1971. In 1979, the Chinatown Historic Area Planning Committee sponsored a streetscape improvement program. Chinese-style elements, such as tile red street lamps and specially paved sidewalk crosswalks, were deliberately added, reflecting the City's current appreciation of Chinatown as a civic asset.