What type of american dog?

I have to draw an animal for history homework that's from America.
My teacher went through loads of different animals and chose one for all of us.
Mine was a rather large, curly coated dog that looked quite like an English Sheepdog, although I can't...

remember the type of dog it was )=
Help is appreciated! ^_^

alil more info please

Ok ^_^
I said before it looks kind of like an English Sheepdog, but it's coat isn't as long as an English Sheepdog. It's coat is extremely curly. In the picture I saw, half of each leg was black then it changed to white as it went further up the leg. The head looks to me as if it's a bit small compared to the rest of the body. I couldn't see the ears, either because they were short or the coat covered them. I couldn't see the tail because of the angle of the camera.
That's all I can remember.

So the dog breed is from america, I've been looking and can only find a curlyhaired retriever kind of dog. Will keep searching. If you can possibly find anything else out I can help you more xo

Two breeds that originated in the USA are the Boston Terrier and the Chesapeake Bay Retriever

Was it the Newfoundland? That was the breed of dog that accompanied Lewis and Clark on their journey. Maybe that's why she picked that breed?