↑ Mack Trucks Advertising Art by Peter Helck (1942–1945)

Mack Trucks Ad (1942): It goes on... And on... And on! - Illustrated by Peter Helck

Mack Trucks Ad (1942): It goes on... And on... And on! - Illustrated by Peter Helck

Mack Trucks Ad (1942): It goes on... And on... And on! - Illustrated by Peter Helck

Mack Trucks Ad (May, 1942): Little chip off a rugged old block... - Illustrated by Peter Helck

Mack Trucks Ad (November, 1942): Made-to-Order for the World's Toughest Customer... - Illustrated by Peter Helck

Mack Trucks Ad (December, 1942): Pouring it on... Mack Style - Illustrated by Peter Helck

Mack Trucks Ad (June, 1943): Four and one-half million strong! - Illustrated by Peter Helck

Mack Trucks Ad (September, 1943): War Report... With a Peacetime Twist!... - Illustrated by Peter Helck

Mack Trucks Ad (October, 1943): Can a Mack really take it? Listen... - Illustrated by Peter Helck

Mack Trucks Ad (November, 1943): Where Steel is King!... - Illustrated by Peter Helck

Mack Trucks Ad (1943): Its middle name is... Work! - Illustrated by Peter Helck

Mack Trucks Ad (1944): Little Macks are "giants" too - Illustrated by Peter Helck

Mack Trucks Ad (May, 1944): No time to gamble... - Illustrated by Peter Helck

Mack Trucks Ad (December, 1944): The Toughest Jobs are Yet to Come... - Illustrated by Peter Helck

Mack Trucks Ad (September, 1945): Does your child ride a Bus to school? - Illustrated by Peter Helck

Mack Trucks Ad (November, 1945): Do you expect enough from your trucks? - Illustrated by Peter Helck

Images: jumpingfrog.com; www.wjm2234.com; www.armorama.com