It had said that it had the 1 TB capacity, or whatever number is slightly under that since none of the drives hold exactly up to what they're listed. The 950 GB was just too much for it since I had loaded about 100 GB on it before attempting that folder.
I think I might have found the problem though. In my Movies folder, I have a Final Cut Library file called "Macintosh HD's projects and events." It is 451.91 GB. Then above it, I have a folder called "Macintosh HD's Old Final Cut Projects and Events." It is 495.9 GB. So, I am currently copying over that folder to my external drive. Then I am going to erase it from my internal hard drive and see if that does the trick. Unless you see that being a terrible idea. It's where the problem seems to be stemming from. The only thing that I'm curious about is how are they both allowed to exist on my internal hard drive?