Walker's rise to prominence was further accelerated by his appointment by Charles Francis Adams, Jr. as the Chief of the Bureau of Awards at the 1876 Centennial Exposition in Philadelphia. Previous world expositions in Europe were fraught with national factionalism and a superabundance of awards. Walker imposed a much leaner operation replacing juries with judges and being more selective in awarding prizes. Walker won formal international recognition when he was named a "Knight Commander" by Sweden and Norway and a "Comendador" by Spain. He was also invited to serve as Assistant Commissioner General for the 1878 Paris Exposition. The Centennial Exposition affected Walker's later career by greatly increasing his interest in technical education as well as introducing him to MIT President John D. Runkle and Treasurer John C. Cummings.