© Bibliothèque et Archives nationales du Québec, digital coll. http://bibnum2.banq.qc.ca/bna/illustrations/detail/3117.jpg.
Before the St. Lawrence Seaway was built, the trip between the Great Lakes and eastern Québec could not be done on just one boat. Some ships navigated the stretch between the Great Lakes and Montréal, while others went between Montréal and Québec. The largest ships would continue on to Tadoussac, and sometimes even farther.
To avoid the lengthy manoeuvring of docking, steamers would meet in the middle of the river, around Québec, to allow passengers coming from the west to change boats to continue their eastbound journey.