Baltimore‘s heyday as a port of immigration was roughly 1870 to 1914, when WWI stemmed the flow. By 1913, an average of 40,000 immigrants came through Baltimore each year.
Sources: Forgotten Doors: The Other Ports of Entry to the United States, ed. M. Mark Stolarik (Philadelphia: Balch Institute Press, 1988); Immigrating to the Port of Baltimore,
http://www.clis2.umd.edu/~mddlmddl/791/communities/html/pob.html; “Immigration Era, Part I: Port of Pleasant Landings,” Baltimore historical Society,
http://www.historicbaltimore.org/program/immigration.htm; William Connery, Point of Entry: Baltimore, the Other Ellis Island,
After a voyage where you were seasick much of the time due to rough weather, you finally arrive in the Chesapeake Bay. Public health inspectors board the ship as it enters the bay and begin physically inspecting the passengers (Esslinger 1988). They are looking for illnesses like typhus, cholera, smallpox, tuberculosis, and trachoma.
Luckily, you were warned before the voyage by a knowledgeable fellow traveler not to bathe in seawater which causes red eyes which many inspectors mistake to indicate trachoma (Brugger 1988). The ship berths at the B&O immigrant pier at Locust Point, and you are allowed to enter the terminal. Over the next several hours you are interviewed and issued papers by immigration inspectors, your baggage is poked and prodded, and you are finally able to leave.
Unlike at Ellis Island, immigrant processing at Baltimore was conducted by private companies. Immigrants with steerage tickets were inspected at Locust Point, but their examinations were considered much more cursory than those conducted at Ellis Island. To make transition between sail and rail easier, B&O Railroad constructed buildings that served as the end of both steamship and rail lines – so passengers could get off the boat, pass through the inspections and then board their train west.