Plenty, but way far outnumbered by bridges. Going back 100, 150, 200 years it was almost all ferries, but as you imagine as more people were about the ferry couldn't keep up with the traffic.
Here in ATL a lot of roads are named for where they lead (or used to lead): Nesbit Ferry Road, Johnson Ferry Road, McGinnis Ferry Road... That would be across the Chattahoochee River, which is perhaps 40-50 meters wide mostly around here. Now there's bridges, no ferrys anymore, but as expected there are only so many, so you might have to travel a little bit to get over the river on a bridge.
Ferries in the Northeast are only financially viable if they save a lot of driving. So there is the Bridgeport (CT) - Port Jefferson (NY) ferry across Long Island Sound, I guess about 20 miles, but saves around 100 miles of driving...and the ferry drops you a few meters from the rail station that goes into New York City. And, similarly, the Cape May (NJ) - Lewes (DE) ferry, also about 20 miles, but saves 170 miles or so.
Lately, if you ever visit New York City, hop a ride on the Staten Island Ferry. Outside rush hour, it is pleasant and uncrowded, and goes right past the Statue of Liberty, with awesome views of downtown NYC - and it is completely free for foot passengers. No tickets, no nothing: Just show up and walk on. (Just like folks trying to sell you the Brooklyn Bridge, scammers will try to sell you ferry tickets.)