This seems like a niche history about nine German-Jewish families (well 8 German Jewish families and 1 Germanic-Swiss Jewish family... the Guggenheims) in New York City, from 1840 to 1930, but in the telling of it, the book delves into general history of America and Germany in that time period, exploring (because of the families' various businesses) the rise of the large railroad combines and the rise of "finance Capitalism" (i.e. capitalization of the country's industry through large Wall Street brokerage houses and consumer banks)
There is also an interesting exploration of Jewry in NYC going back to the period of Dutch rule in "New Amsterdam". The Spanish Inquisition expelled Jews from Spain in 1492. Most of these were Sephardic, and found refuge in Brazil (a Portugese colony with liberal immigration policies towards anybody who looked like they would develop the land and firmly establish the Portugese claim on it.) Portugal lost Brazil to Spain in 1668, under the terms of the Treaty of Libson. With the Inquisition still in force, the Sephardic Jews were expelled, and most of them found refuge in New Amersterdam.
As a result, the face of the Jewish community in New York was decidedly Sephardic from the 1600's until the 1840's, when a revolution in Germany resulted in a mass influx of German immigrants to New York. Most of the Jews arriving in this wave were Ashkinazi, and they were not warmly welcomed by the Sephardics.
This is a large undercurrent narrative in the book, with Germans having to build parallel synogogues, Hebrew schools, etc, and the cultural characteristics of New York Jewry transforming from the Latin, more insular, Sephardic subculture into the decidedly more open (i.e. assimilationist) Germanic, Yiddish-speaking, Ashkinazis.
One thing this book is NOT, is a telling of the Jewish experience across the socioeconomic spectrum. The book is dedicated to nine of the wealthiest families in the City, whose names are tied up in the founding, running, and in some cases decline of some of the largest and most successful companies of the 1800's, including: Goldman and Sachs, the Guggenheims (whose metalworking and mining fortunes persist today in holdings of US Steel, Newmont Mining and Barrack Gold), Kuhn & Loeb, Solomon Brothers banking and brokerage, Harriman Brothers, Macy's department stores, and a railroad empire which has since been absorbed into Union Pacific.
In this sense, it is a specialty History with a narrow focus, but probably still broad appeal. Who doesn't love hearing about the dramas and infighting of the super-rich? Every chapter is like an episode of "Dynasty" or "Dallas." (Do those references date me? I don't know what the current-day equivalents are.) Still, as noted above, the telling of it all covers a lot of general history which should be of interest to a wide audience.