The Boy Scouts of America have existed for just over a century. When it first published a manual in 1911, the organization offered 57 merit badges. Now, if offers 131. In general, the requirements have gotten more specific over time. Brett and Kate McKay write at The Art of Manliness:
Modern badge requirements also diverge from the old in their more abstract, mental nature. While the 1911 badge requirements are all direct actions, often of the physical, hands-on variety, the modern badge requirements emphasize more thinking than doing. The hands-on tasks are now tucked into long lists of requirements that ask the scout to thoroughly Review/Describe/Explain/Illustrate/Demonstrate the underlying principles and context of the badge’s subject matter before trying their hand at it. [...]
Camping is the activity for which the Boy Scouts are best known. In comparing the original camping merit badge to today’s, one can see how the hands-on requirements have been loosened; for example, Scouts formerly had to sleep out for 50 nights, know how to build a fire without matches, and construct a raft. On the flip side, the modern badge has decreased that requirement to 20 nights, and has greatly expanded the more mental requirements — making checklists, creating plans, and describing different camping guidelines and pieces of equipment.
P.S. The entire 1911 Boy Scout manual is available online here.