Do you need a business major to go to business school?

I went to Baruch College, a CUNY school, and got my BA in History.

Going from a political science degree into law school is a very valid and notable route.

is it the same for a graduate business school?
You should be able to go into the business graduate school while not having a BS or a BA in Business. But you will probably have to take a few more business related prerequisites required by the graduate school in order to qualify in their eyes.

Management is a very general term and can be broken down more specifically.

My major is project management (Six Sigma methodology) but I deal a lot with Global (international) management, business law, human resource management, call center management, small business, technology solutions, etc.

If you have a specific focus like, law it will probably make things much easier in the selection of specific courses for you but in the long run you won't be able to ignore the others. They are all interconnected. The more flexible you are across the various management areas will give you more to go on in the International management side of things.

I know it used to be. Way back in '73 I was accepted into the MBA program at
Northeastern and I held a BA in Scholastic Philosophy.