David Isaac Dobnievski was born February 22, 1892, in Brest, in what was then the Russian Empire (and is now Belarus), as the youngest of five boys and three girls.

David's father, Bezalel Dobnievski, a religious Jew, owned a bakery, but limited himself to administrative tasks related to the enterprise.

David worked from early childhood delivering bread from his father's bakery to local shops, while attending a Hebrew school, where he studied Polish, Russian, and Yiddish.

He was later forced to leave a semi-private school he attended to take work in his father's bakery to replace a brother who had left abruptly.

[4] In 1906 or 1907,[5][6] Dubinsky was arrested by the Okhrana, and was held for 18 months in prison before being sentenced to hard labor in Chelyabinsk, Siberia upon reaching the age of 16.

He quickly rose to become a sewing machine operator, but ignored requests from relatives that he pursue a career in the medical industry, and did not join his brother as a baker.

Instead of these tasks, Dubinsky continued in the garments trade alongside tens of thousands of other Jewish workers, and became a member of Local 10, the ILGWU's cutter's union.

Dubinsky campaigned hard for election of Morris Sigman, a former Industrial Workers of the World (IWW) member who took office in 1923.

Sigman began to remove Communist Party USA members from leadership of locals in New York, Chicago, Philadelphia and Boston.

Dubinsky, by his own account, thought that Sigman was too rash and appears to have urged him to call a truce after the left wing-led unions led a campaign to reject a proposed agreement that Sigman had negotiated with the industry in 1925, bringing more than 30,000 members to a rally at Yankee Stadium to call for a one-day stoppage on August 10, 1925.

That strike was a disastrous failure, leading to the rout of leftist leadership from the Joint Board and ultimately from the industry, other than the independent International Fur Workers Union.

At the 1928 convention of the ILGWU he first proposed that Sigman resign in favor of Schlesinger – a suggestion seen by many as part of a plan by Dubinsky to become the eventual head of the union.

Dubinsky denied any personal ambitions and rebuffed a proposal from Abraham Cahan of The Forward to promote him as Sigman's heir apparent.

Dubinsky set out to rebuild the ILGWU's base in New York City by striking a deal with the major manufacturers' group in 1929 that provided no pay raises but made it possible for the union to police the contract by cracking down on subcontractors who "chiseled", cheating workers out of pay or hours in order to gain a competitive advantage.

He was elected president after Schlesinger died in 1932,[8] retaining the position of Secretary-Treasurer in order to avoid the sort of internecine battles that previous officers had waged in the past.

He did not brook dissent within the union and insisted that every employee of the International first submit an undated letter of resignation, to be used should Dubinsky choose to fire him later.

The union recovered, however, after the election of Franklin D. Roosevelt and the passage of the National Industrial Recovery Act, which promised to protect workers' right to organize.

Some of them, such as Lepke Buchalter remained in the industry as labor racketeers who took over unions for the opportunities for raking off dues and extorting payoffs from employers with the threat of strikes.

The union's membership also changed greatly in the years after World War II; what once had been a predominantly Jewish and Italian workforce became largely Latino, African-American and Asian.

The union continued to expand its membership after World War II, reaching its apex at 500,000 members in 1965, one year before Dubinsky's retirement.