DuPont declared a first quarter common stock dividend of 38 cents per share payable March 14, 2017, to stockholders of record Feb. 15, 2017. This is the 450th consecutive quarterly dividend since the company’s first dividend in the fourth quarter of 1904.   Regular quarterly dividends of $1.12-1/2 per share on the $4.50 series preferred stock and $0.87-1/2 cents per share on the $3.50 series preferred stock also were declared, both payable April 25, 2017, to stockholders of record April 10, 20...