The refuge site describes the history of the cams:
In 2001, the Friends of Blackwater embarked on a new project whereby they mounted a small camera on an osprey nesting platform near the Wildlife Drive at Blackwater Refuge. Images were then wirelessly transmitted to a monitor at the Visitor Center and also to the Friends of Blackwater website. Every season since 2001, the Friends have operated the Osprey Cam and allowed visitors at the Refuge, and on the Friends' website, to witness the miracle of seeing numerous osprey chicks hatch and fledge.
Due to the overwhelming success of the Osprey Cam, the Friends decided to mount a camera over an active bald eagle nest on the Refuge property beginning in 2004. The live Eagle Cam has proven even more popular than the Osprey Cam, and numerous eaglets have hatched and fledged on the cam.
Currently the Eagle Cam is live from December through July (when the eagles are at the nest), and the Osprey Cam is live throughout the year, even though the ospreys are only on the nest from March through September. After the ospreys migrate to South and Central America in the fall, bald eagles take over the osprey platform and use it as a riverside perch, so the Friends leave the Osprey Cam on all year to allow cam watchers to see the visiting bald eagles.
The Osprey Cam is here.
The Eagle Cam is here.
I love this kind of technology because it allows us the opportunity to see something that we would otherwise have the opportunity to see.
UPDATE 2/15: Was transferring my favorite birding blogs to a different RSS feed provider and came across this post by Nervous Birds about an afternoon of birding at Blackwater NWR. Some nice photos!