Still catching up — the David Rumsey Map Collection announced last month that it has added over 550 new maps to its online collection.
You can get a list of all the new maps here. A nav on the right shows you the kinds of maps available, including national maps, physical maps, and atlases. As you make selections your search options narrow down further. You can also choose by place mapped, date, and cartographer.
via researchbuzz.org