Although he is almost forgotten in his home state of Massachusetts, Clark remains a national figure in Japan. His influences on the agricultural and economic development of Hokkaido were significant, but it is primarily his cultural message that still resonates today. According to historian Fumiko Fujita, Clark's phrase, "Boys, be ambitious!" is "almost immortal in Japan." The Japanese National Tourism Organization describes the slogan as "famous" and often quoted throughout the country. Historian John Maki wrote that many Japanese school textbooks "have carried brief accounts of [Clark's] work and his slogan", and that Clark's name appears on "schools, buildings, shops, confections and countless tourist souvenirs."