This comes from the Clarke County Historical Society Quarterly, Summer 1991.I am not sure if this William C. Windham is your William Windham:
C C D [Clarke County Democrat] 28 February 1856 Vol. 1 # 5
Murder!We are pained to announce that on last Saturday, at Jackson, in this county, WILLIAM C. WINDHAM was shot dead by CAPT. B. F. DUNCAN.They were both residents of JACKSON.The unfortunate result we learn grew out of a pecuniary difficulty.At last accounts the perpetrator of the awful deed was at large and no steps had been taken for his apprehension.