Here's a 1970s public service announcement for the United States Marine Reserve. This is a recruiting ad, an attempt to get people to enlist as military personnel in the US Marine Reserve. 

Shows men in military fatigues, doing things as a group while being accompanied by 3 little kids. Everyone looks exceptionally cheery. The men lift logs and cut logs. With the kids, the men push a log down a hill. A tractor pushes dirt aside.

A wide shot shows the men putting the finishing touches on a playground-like structure, a kind of jungle gym made with logs stacked on each other.

In the final shot, the men and kids run up a hill and the following text appears on the screen: “MARINE RESERVE 800-423-2600.”