Thanks George!
I've looked all over the internet all day and I couldn't find anything about this one. I did find a pint jar like it on ebay, but no info.
This jar is known as a "Ball the Mason" jar and is a reworked mould. Ball bought the Mason Fruit Jar and Bottle Company of Coffeyville, Kansas (the company that made 'The Mason' jars) in 1909. They reworked their moulds by simply adding the Ball name above the existing embossing making these "Ball the Mason" jars.
These come in 3 sizes: pint, quart and half gallon. Two or three colors and two types...the shoulder seal as your jar and also a bead seal type which is much more scarce. Ball closed the Coffeyville plant in about 1913 so your jar would have been made c1909-1913.