Being a time of turbulence and change, stretching from when the "bouncers" were becoming rich at too quick a rate for them to be absorbed into Society to when the Great Depression meant not all were a number no longer rich but the rest toned down the ostentation.
It also covers regional variations. Like the acceptability of a Bostonian young man going into art instead of law or banking -- certainly not acceptable in New York City. In some cities, you could be a denomination other than Episcopalian -- Quakers for Philadelphia, Presbyterians in New York, Congregationalist or Unitarian in Boston -- but Episcopalian was always acceptable, and in New York, when they chose where to open a church, where was fashionable shifted to follow it.
The gentle art of distinguishing who was acceptable and who not -- Catholics and Jews were problems. But Catholics in certain cities were the old families, and many Protestant heiresses opted to buy themselves Catholic noblemen in Europe, so they became acceptable even as attitudes against Jews were hardening. An Englishman found it hard to figure out the rules. Partly because neither politics nor military service cut any ice in America. Societies of early settlers were sometimes a mark, but neither the Sons nor the Daughters of the American Revolution really worked because too many of the people-we-don't-know could lay claim to that honor.
Filled with details on their lives. Education -- prep schools and college for the boy; at home for the girls, some boarding schools opening in the later period. And the exclusive clubs thereafter. Though the women's were only in the later decades. Their fashions, deliberately impractical. The fashion for chaperons in this time. Before this, it had never been an American tradition. The servants. The fashion for dark colors for rooms, which looked rather worse after electricity came in, and the changes in fashion for the decoration.
Going aboard with the fearful danger of having to live in a hotel, which, even if the proprietor tried to aim for the upper crust, still might be filled with people-we-don't-know. Impoverished upper-crust Americans sometimes made a living by smoothing things for their richer fellow Americans.
Their resorts. The extravagance of Newport, where the up-and-coming were advised that the best way to come was by yacht, and live on it, so they could depart with some grace if utterly snubbed. You needed 240 dresses for a sixty day season there. The concerted respectability of Bar Harbor, where young men and women could adhere to the respectable American custom of unchaperoned walks in the woods, and go out in a boat together, provided it was broad daylight, they could be seen from the deck, and the boat had oars, not sails, so they couldn't be becalmed -- and you could respectably stay in a hotel. The first country clubs, and the Adirondacks, and Saratoga Springs, where men watched races and women got to sit around.
Some were charitable, some were not. Others went in for art -- but not artists.
And the Society Pages, the horror of high society. Including one writer with a charming tendency to blackmail.
Filled with anecdotes, like:
A woman who would invite her sons to dine with her, in full formal dress, when their father wasn't home. They could opt for their usual diner, but she never relented on the requirement.
Tin tubs that were kept as sparkling as the silver, so it was like bathing in silver.
At the opera, the names of those who had taken boxes were printed in the program.
If your ship passed another on the Atlantic, you could send a "Macronigram" to those you knew on board.
One survivor of the Titanic recorded in her account whom she knew in the lifeboat she took from the sinking ship. (Her husband drowned. They had to argue her son was only thirteen before he was allowed on the boat.)