Marco is the protagonist of the play, yet Eugene O'Neill does not hesitate to expose him. Marco is a grotesque character, a wealthy merchant. Every action he takes is aimed at profit.

Even when he finds love and romance in exotic places, he is unable to see beyond and only continues to increase his wealth, seeking the respect of his relatives and ultimately marrying his childhood sweetheart.

At times, Eugene O'Neill presents his hero as so ignorant and so pedestrian that one wonders what those who love him see in him. It is a historical drama that critiques the attachment to material goods.

Together with The Fountain, it is one of O’Neill's unique plays, featuring two explorers from the past as heroes. In The Fountain, we have Ponce de León, the Spanish conquistador, and here, the Venetian merchant Marco, who travels to China.

The play The Millions of Marco Polo was published in 1927 and was staged the following year in the theater. The directorial execution posed a tremendous challenge for the time, as it was an expensive, demanding production.