Saint Lawrence Boulevard or boulevard Saint-Laurent (its official name, in French) is a major street in Montreal, Quebec, Canada. A commercial artery and cultural heritage site, the street runs north-south through the near-centre of city and is nicknamed The Main.
Beginning at De la Commune Street at the edge of the Saint Lawrence River, it crosses the whole island through the boroughs of Ville-Marie, Le Plateau-Mont-Royal, Rosemont—La Petite-Patrie, Villeray–Saint-Michel–Parc-Extension, and Ahuntsic-Cartierville to Rue Somerville at the edge of Rivière des Prairies– a total length of about 11.25 kilometres.
St. Laurent Street became a boulevard in 1905, and is affectionately referred to as The Main by many Montrealers. It serves as the city's physical division of east and west. Street numbers begin at Saint Lawrence and continue outward, with street names being suffixed by Ouest (West) or Est (East), depending on their orientation.
The street traditionally divides Montreal by language, ethnicity, and class. Saint Lawrence Street was for generations the symbolic dividing line for the city, with the predominantly English-speaking population to the west, French-speaking population to the east, and immigrant communities in between along the Main and Park Avenue. The Main runs through many of Montreal's ethnic communities, a first stop for immigrant communities for over 100 years — initially Jewish, Chinese and Italian, and later Portuguese, Greek, Arab, Haitian and others.
The southern section of the street in downtown Montreal and the Plateau is lined with trendy shops and restaurants, and is the site of many street-fairs and festivals. What were once run-down factories have been turned into expensive lofts. Saint Lawrence Boulevard is representative of Montreal's shift out of the economic decline in the 1980s and 90s.
In 2002, the Historic Sites and Monuments Board of Canada named Saint Lawrence Boulevard as The Main National Historic Site of Canada. Then Minister of Heritage, Sheila Copps, speaking at the ceremony, said: "our country does not belong to just two founding peoples. It belongs to all Canadians. [This is] a first step toward a new story of Canada that includes all of our partners as equals." 
|“||All day long, St. Lawrence Boulevard, or Main Street, is a frenzy of poor Jews, who gather there to buy groceries, furniture, clothing and meat. Most walls are plastered with fraying election bills, in Yiddish, French and English. The street reeks of garlic and quarrels and bill collectors: orange crates, stuffed full with garbage and decaying fruit, are piled slipshod in most alleys. Swift children gobble pilfered plums; slower cats prowl the fish market. — Mordecai Richler, Son of a Smaller Hero ||”|
The Jewish community on the Main sprang up after the heavy immigration of the early to mid-1900s. Jewish settlement occurred first on the lower Main, in an section that now is part of Montreal's Chinatown.
By 1871, a Jewish enclave numbering just over 400 people had formed by the corner of St. Lawrence and Dorchester Street, with the first Jewish educational institution, the Talmud Torah, located at the corner of Saint Urbain Street and De la Gauchetière Street. Middle class members of the community were already beginning to move up the Main towards Sherbrooke and Prince Arthur Streets, while further north, a small number of well-off Jews lived near McGill University.
The main axes of Jewish quarter were Saint Laurent Boulevard, Clark Street, Saint Urbain Street, Esplanade Street and Park Avenue, Montreal. By the 1920s and 30s, dozens of synagogues were in the area. Landmarks on Saint Laurent that bear witness to this historic community include Schwartz's delicatessen.
Yiddish was the common language in the Jewish district on Saint Laurent Boulevard, with many Jewish immigrants working in clothing factories, once the street's main industry. Overall, Montreal was the main destination for the 125,000 Jews that settled in Canada between 1905 and 1920, making the area a centre of Yiddish language and culture. Despite Canada's poor record of Jewish immigration between 1933 and 1948, Montreal would also become home to the world’s third-largest concentration of Holocaust survivors, most of them Yiddish speakers.
The district was home to the second largest Yiddish theatre in North America from 1896 to the 1940s, with shows at vaudeville houses along the Main, as well as the Monument National — now a National Historic Site and part of the National Theatre School of Canada. 
The Main was also a centre of Jewish publishing. In 1907, a young Polish Jewish immigrant Hirsch Wolofsky started the Yiddish language daily newspaper Keneder Odler (English: Canadian Eagle). The paper was initially published from an office on Saint Laurent near Ontario Street. However, with the success of Keneder Odler, Wolofsky soon moved his paper to its own building at 4075 Saint Laurent, near Duluth Street. The paper would publish for more than 50 years. Today, Wolofsky is remembered with a small park in his honour at the corner of nearby De Bullion and Roy streets.
The poor Jewish quarter had a distinctly left-wing slant. Fred Rose represented the Main’s Cartier riding until 1947, when he was expelled from the House of Commons after a controversial conviction on charges of spying for the Soviet Union. To this day, the Main remains the only part of Canada ever represented in Parliament by a Communist.
Area city counselor Joseph Schubert, a Romanian Jew, was a socialist and admirer of Karl Marx. Elected to Montreal City Council in 1924, he was the council’s most prominent advocate of worker’s rights for 15 years. In 1931, he built a public bathhouse at the corner of Bagg and St. Lawrence, which still stands today as the Schubert Bath (official French name: Bain Schubert).
By the 1950s, many Jews had moved to other communities and most shuls were demolished or converted to other uses. Former prominent Jewish-run businesses on the street included Ida Steinberg’s grocery store, founded in 1917 on St. Lawrence near Mount Royal, which went on to become Steinberg's, Quebec’s largest supermarket chain. Another supermarket, Warshaw's, was recently the subject of controversy when the city of Montreal was forced to pay damages after first approving and then rejecting changes to its iconic storefront. As of 2003, fewer than 10 Jewish-owned and family-run businesses remained on the Main between Sherbrooke Street and Mount Royal Avenue.
Today, Saint Lawrence is home to Little Italy (between Saint-Zotique and Jean-Talon streets), Mile End between Mount Royal and Van Horne Avenues, Montreal's Little Portugal, clustered around Duluth and Rachel Streets, a bar district (roughly between Sherbrooke and Duluth streets), a small red-light district and Montreal's Chinatown (between Viger Street and René Lévesque Boulevard).
The Main has produced many of Canada's most prolific individuals in the arts and has acted as a memory space. Novelists Mordecai Richler and Michel Tremblay and poets Irving Layton, A. M. Klein and Leonard Cohen were all influenced by this area. Canada's most prestigious award for fiction, the Scotiabank Giller Prize, was named after journalist Doris Giller, a native to the area.
Sass Jordan's 1992 hit single "Going Back Again" also depicts Saint Lawrence Boulevard as the dividing line between Montreal's English and French cultures, expressing the hope that "Someday we will come together/Reach across this great divide". Trevanian's 1976 novel The Main is set in the more run-down district of the sixties, before the modern renaissance.
Numerous art galleries and other cultural organizations make their home on the Main. including La Centrale/Powerhouse (Canada's oldest women's artist-run centre), Ethnik-art, the Festival du Nouveau Cinéma, Festival International Nuits d'Afrique, the Montreal Fringe Festival, Image & Nation Festival, My Hero Gallery, the Society for Arts and Technology and Sensation Mode. Many well-known music venues can be found on the Main, including Casa del Popolo, Sala Rosa, Club Soda, Barfly , Jupiter Room, Main Hall , Club Lambi, The Academy Club and Divan Orange. The street is also home to the National Theatre School of Canada as well as the EXcentris arts complex, adjacent to the offices of Softimage. Gastronomic highlights include Montreal's famous smoked meat deli Schwartz's as well as the Montreal Pool Room, serving Montreal hot dogs since 1912.
The Société de développement du boulevard Saint-Laurent (SDBSL) is a merchant's association the promoting economic, social and cultural development of Saint-Laurent Boulevard between Sherbrooke Street and Mont-Royal Avenue.
The corner of Saint Lawrence and Saint Catherine streets is still known as a red-light district, although its days appear numbered as a proposed $167-million development is slated to transform the area, now part of the city's new Quartier des Spectacles.