At college he joined the swimming team and the dramatics club, and served on the editorial board of the Harvard Monthly and Lampoon, and was class orator and poet. After graduating from Harvard in 1910 Reed travelled in England and Spain and upon his return to America started his career as a journalist in the leftist magazines.
Aided by Lincoln Steffens, he obtained employement with The American Magazine, but he submitted his most sincere work to The Masses.
In 1913 Reed published his first book, Sangar, a collection of poems. In 1914 he was arrested for trying to speak for striking silk worker in Paterson, New Jersey and wrote then The Pageant of the Paterson Strike, which was enacted at Madison Square Garden, as a benefit to aid the workers. Reed was arrested several times for organizing strikes and he soon became a radical leader.
His report of the Paterson silk mills strike won him recognition, and in 1913 he was sent by the New York World to cover the Mexican revolt of Pancho Villa. As war correspondent during WWI he wrote articls republished in The War in Eastern Europe.
Already sympathetic with the cause of the Russian revolution, Reed became friendly with the Bolshevik leaders and was an eyewitness to the 1917 October revolution, recording this event in his best-known book Ten Days That Shook The World. He then returned to America to be active in the organization of the first Communist Labour Party of the US, and was founder and first editor of the Voice of Labour.
When the Communist Party and the Communist Labor party split in 1919 Reed became the leader of the latter. After charges of treasons he fled America by ship to Finland where the authorities kept him in prison before exchanging him for Russian-held Finnish prisoners of war.
In prison Reed wrote more poetry and outlined a pair of novels, which he never completed.
In Russia he gave speeches and became a close friend of V. I. Lenin. At the peak of his career Reed was stricken with typhus and he died. Reed's popularity as a radical leader led to the creation of John Reed clubs across the United States.
Reed was accorded the honor of burial with other Bolshevik heroes beside the Kremlin wall. His life was subject for the successful 1981 motion picture Reds.