I found the available answers online for this question to be pretty vague and confusing for a non-command line ninja. Rest assured though, it is very easy to do. There’s a $20 program out there that will do this, but I found it to be pretty clunky and … un-free.
1. Put all your CSV files in one folder. For this example let’s put all CSV’s to be merged in a folder called “a” in the “Downloads” folder. (As a result the path to this folder is: C:\Users\yourusername\Downloads\a)
2. Press Windows Button+R (or click the start button and search for “run“)
3. Type in cmd and press OK
A command line window will pop up (scary DOS stuff, I know. Stay with me)
4. Now grab the path to the folder with all your CSV’s inside. To do this click on the address bar of the window and copy the text.
5. Now back to your command line and your cursor should be waiting for you right after C:\Users\yourusername>
6. Type in the following command (you can paste the folder paths from step 5 and just type the stuff in red):
copy C:\Users\npierno\Downloads\a\*.csv C:\Users\npierno\Downloads\a\Output.csv
(The basic structure to follow is: copy <your folder path>\*.csv <desired output folder path>\desiredfilename.csv)
7. Press enter, and you’re done! Check the chosen output folder (in this case “a”) for your Output.csv file!