Most of the photos on this site were extracted from reference images (high-resolution tiffs, 20 to 200 megabytes in size) from the Library of Congress research archive. (To query the database click here.) Most were digitized by LOC contractors using a Sinar studio back. They are adjusted by your webmaster for contrast and color in Photoshop before being downsized and turned into the jpegs you see here.

Circa 1903. "Baltimore from Federal Hill." A freight terminal (O'Donnell's Wharf) and the Patapsco flour mill. Detroit Publishing Co. glass negative. View full size.
Baltimore looked grim then, and is far worse now, from personal experience.
Just one year before the Great Baltimore Fire destroyed much of what you're looking at. Amazing.
The little two-masted sailing vessel to the left of the Northern Central warehouse seems to be filled - with people? An excursion, perhaps? Seems a funny place to be starting from, but the boat is too far from the dock to be anchored there.
The crenelated "smokestack" to the right of the power plant is the Phoenix Shot Tower, from 1828 until the 1880s the tallest structure in the USA. The neighborhood to the right of the picture is "Little Italy" (correct Bawlmer pronunciation: "LiddleIddlee") which is now among other things a concentration of restaurants.
You can still see power plant though the Northern Central Freight Stations building was replaced by something more modern.
The Arthur Andersen office used to be there and have a glass center wall that overlooked the Barnes & Noble.
I love the waterfront photos on Shorpy! The three-master in the center is a beautiful boat, I would love to have seen her under sail!
Looks to be taken from roughly the location of the Rusty Scupper Restaurant on the south side of the Inner Harbor, near where the Key Highway bends around from west to south. The National Aquarium in Baltimore now occupies the space where Pier B's two buildings are, as well as the Northern Central Freight Station pier.
This is where a young George Herman Ruth got into all that mischief which led him to St. Mary's Industrial School for Boys. There, he met a gentleman named Brother Mathias who taught him the game of baseball.
The powerplant across the Inner Harbor still exists, now as a venue for night clubs and sports bars, including the Hard Rock Cafe and an ESPN Zone. Of course, the harbor is no longer a working harbor.