The Red Star Line was the steamship line founded in 1873, by Clement Acton Griscom, a Philadelphia Quaker. The line was a joint venture between the International Navigation Company of Philadelphia, which also ran the American Line, and the Societe Anonyme de Navigation Belgo-Americaine of Antwerp, Belgium. The company's main ports of call were New York and Philadelphia in the United States and Antwerp in Belgium.
The ships of the International Navigation Company flew a flag with a red star, hence the company became known as the Red Star Line.
Philadelphia was one of the major terminals due, in part, to the founders and the financial backers being in Philadelphia. Griscom was a life-long Philadelphian. One of his ancestors arrived in America before William Penn and was an associate of Penn's. The major financial backer was the Pennsylvania Railroad.
Antwerp was selected as the European terminus, because it was at the center of the major manufacturing countries of Europe. The Belgian government wanted to attract more migration traffic via Antwerp giving active financial and logistic support to steamship companies. Griscom found King Leopold II of Belgium to be a willing partner. He granted the new company a monopoly on postal traffic and extended subsidies. The city of Antwerp also gave exemption from warf and piloting fees.