Geotechnical Special Publication No. 111 contains six papers of timeless value from some of the most experienced leaders of the geotechnical engineering profession. The papers reflect over 250 years of collective geotechnical engineering experience. The topics include historic and futurist views of the profession, strength and slope stability analysis, internal erosion and piping, field and laboratory measurements in geotechnical engineering, and geoenvironmental engineering and its impact on geotechnical practice.