Combine text files eliminating duplicate lines

Dave Behman posted code for a Windows batch file here, which can be used to combine two text files and eliminate any duplicate lines.

So let's say you have one text file like this:

. . . and a second text file like this:

. . . and you want to combine them into a single text file which only lists each U.S. president once.

Enter this code in a new text file:

@echo off copy USPresidents1.txt merge.txt >nul findstr /lvxig:USPresidents1.txt USPresidents2.txt >>merge.txt type merge.txt

Save the new text file with the extension, '.bat' and double-click on it. You will get this result: