As a young man of fourteen, Garvey left school and worked as a printer's apprentice. He participated in Jamaica's earliest nationalist organizations, traveled throughout Central America, and spent time in London, England, where he worked with the Sudanese-Egyptian nationalist Duse Mohamed Ali. In 1916 Garvey was invited by Booker T. Washington to come to the United States in the hopes of establishing an industrial training school, but arrived just after Washington died. In March 1916, shortly after landing in America, Garvey embarked upon an extended period of travel. When he finally settled down, he organized a chapter of the Universal Negro Improvement Association and African Communities League. The UNIA & ACL had been formed in Jamaica in 1914. Its motto was "One God, One Aim, One Destiny," and pledged itself to the redemption of Africa and the uplift of Black people everywhere. It aimed at race pride, self-reliance and economic independence.

Within a few years Garvey had become the best-known and most dynamic African leader in the Western Hemisphere and perhaps the entire world. In 1919 Mr. Garvey created an international shipping company called the Black Star Line. By 1920 the UNIA had hundreds of divisions. It hosted elaborate international conventions and published a weekly newspaper entitled the Negro World.

No other organization in modern times has had the prestige and the impact as the UNIA & ACL. During the 1920s UNIA divisions existed throughout South, North and Central America, the Caribbean, Africa, Europe and Australia.