You can get a better understanding of how American culture has changed in the last 100 years by looking at the changes in one organization, such as this fascinating comparison of the Boy Scouts of American 1911 and modern handbooks and merit badges:
What has been dropped or reduced in the modern handbook is telling. Gone is the section on chivalry, which traced the Boy Scouts’ heritage back through the pioneers and Pilgrims, and to the knights of the Middle Ages. While the 1911 handbook has a lengthy chapter on Patriotism and Citizenship (including a letter from Theodore Roosevelt on “Practical Citizenship”), which outlines the history of the United States, the meaning of the flag, and the purpose of various governmental bodies, the modern handbook has greatly shrunk the discussion of such things in both length and detail. The original is also generously peppered with references to great men in history for young boys to emulate, while the mention of such “heroes” is almost entirely absent from the one published in 2009 (being inspired by history isn’t much in fashion these days).
Perhaps most striking is the different way in which the two guides address the idea of good character. The original didn’t shy away from strong admonitions like, “It is horrible to be a coward. It is weak to yield to fear and heroic to face danger without flinching,” and “The honor of a scout will not permit of anything but the highest and the best and the manliest. The honor of a scout is a sacred thing, and cannot be lightly set aside or trampled on.”
In contrast, the modern version frames its discussion of character in terms of its inoffensive modern equivalent: leadership and personal development. Instead of being couched in the absolute language of moral virtue, doing the right thing becomes a matter or “making the most of yourself” and “getting along with others.”
The section on merit badges is especially interesting. There are 131 merit badges available today, versus 57 in 1911. Partly that's just because there are more skills one can be tested on these days, but I think it also reflects our "make everybody a winner at something" self-esteem-obsession. Some badges are gone because the skills they represent are no longer relevant -- there was a blacksmithing badge, for example, and one testing semaphore skills. Today there are badges for such things as skating, traffic safety and "game design" (playing and describing what you like about your favorite video games).
