Douglas R. Price W51, a businessman, inventor, historian and writer who had been an aide to President Dwight D. Eisenhower, died on his 87th birthday of complications from Parkinson’s disease at the Blakehurst Retirement Community in Towson. The son of W. James Price III, a partner at Alex. Brown & Sons, and Frances Robbins Price, a homemaker, Douglas Robbins Price was born and raised in Ruxton. After graduating from the Gilman School in 1947, he earned a bachelor’s degree in 1951 in economics from the Wharton School.