If I'm not mistaken, 2D acceleration was offered by video cards even a few years older than the Millennium II. As long as the drivers supported Direct2D (called DirectDraw at the time).
2D acceleration predates DirectDraw actually.
The first Windows acceleration was done in Windows 3.x, via the GDI API.
I didn't say it was THE first, but I said it was 'one of the first'.
S3 was also among the early 2D accelerators, and even late versions of the Tseng Labs ET4000 architecture had some 2D acceleration features.
And if we don't look at Windows specifically... you could even look at some early SVGA cards or IBM's XGA for some amount of 'acceleration', by having special bitblt operations and simple hardware filling.
I agree with you guys that during those days Matrox and ATI had the best 2D image quality and performance, S3 wasn't very far behind though. Nvidia's early cards had worse image quality, but 2D performance improved by the time TNT/TNT2 were released.
The main difference between Matrox/ATi and the others (S3, nVidia, Tseng Labs, Cirrus Logic and whatnot) is that Matrox and ATi didn't use 3rd party OEMs to market the cards, but only built their own, under strict quality control.
Sure, there may have been SOME good cards from the other brands as well, but the majority of the OEMs had very poor quality, even from major OEMs such as Diamond.
With Matrox and ATi, the image quality was guaranteed.