Before 1956 Madhya Pradesh was divided into 4 states namely
Madhya Bharat with its capital Indore(Summer) and Gwalior (Winter).
Central Province and Berar consisting most of today's Chattisgarh, Northern Maharashtra and Southern MP, Baghelkhand region with its Capital as Nagpur.
Vindhya Pradesh consisting the vindhya range region and some of today's U.P with Rewa as Capital
And...
more...
Bhopal State/Bhopal Sultanate consisting Sehore Vidisha and Raisen District with capital as Bhopal city itself.
On 1 november 1956 these state got divided from there UP and Maharashtra part to form current MP and CG as India's then largest state MP with Bhopal as capital.
And on this day itself in year 2000 CG got separated from MP with Raipur as Capital. So this day is also establishement day of Chattisgarh .
Source of Info: Internet and Book