Complex sentence: The word "sneaker" is often attributed to Henry Nelson McKinney, an advertising agent for N. W. Ayer & Son, who, in 1917, used the term because the rubber sole made the shoe stealthy.
Split into simpler sentences: The word "sneaker" is often attributed to Henry Nelson McKinney who was an advertising agent for N. W. Ayer & Son. In 1917, he used the term because the rubber sole made the shoe stealthy.