The Smithsonian Reviews Scouting over the YearsClick here for an article in the October 2018 issue of the Smithsonian Magazine: "Read this story and earn your merit badge in U.S. Cultural history."
You can see pictures of old Boy Scout and Girl Scout merit badges, such as 1911 "Automobiling," with this caption: "Less than 1 percent of the U.S. population owned a car when the Boy Scouts first learned to drive." The "Radio" badge was introduced in 1938 then updated in 1953 as TV started to take off.
In 1920, the Girl Scouts added "Business Woman," but it was mostly about clerical skills. But recently the Girl Scouts launched 24 STEM-related badges, "on topics from cybersecurity to robotics."