There are any number of summaries available online for James Michener's tome of historical fiction that is a panoramic view of the history (400 years) of this beautiful area in the Chesapeake Bay, the largest estuary in the United States that lies off the coasts of Maryland and Virginia.  Like other novels of Michener's, the plot is developed around the families involved in the history of the area. As you summarize, you may wish to organize this summary into its themes of religion, slavery, industry, and poverty.  In this way, people will be better able to follow your thoughts because a discussion of the characters is secondary to these themes since most of the characters are not well developed. These characters do, however, contribute to the development of themes.

Religion

There are two families involved in this theme:  the Steeds, who are Catholic and the Paxmores, who are Quaker.  These families conflict in a debate over slavery, which is a predominant theme, as the Steeds are plantation owners while the Paxmores are among the first abolistionists.

Slavery

This theme centers around one of the Steeds slaves, Cudjo Cater, who eventually buys his freedom, but he is still affected his entire life by conditions relative to slavery.

Industry

Each of the families that come to the Chesapeake Bay area work hard to achieve success and better their lives.  The Steeds, of course, establish their wealth in this area with their tobacco plantation and the many acres of land that they eventually own.  Likewise, the Paxmores develop a boat building business that thrives.  Cudjo Cater obtains work as a cook for na oyster skipjack, and eventually earns enough to buy his own skipjack. The Irish immigrants, the Caveneys work hard in the oyster and duck trades.

Poverty

The Turlocks, who live on the marsh side of the area, exemplify the stereotypical "white trash."  They only rise out their poverty near the end of the narrative as in 1978, one of the Turlocks becomes a real estate broker who sells waterside properties.  Ironically, one of his customers is a returning member of the Steed family who wishes to reclaim some of the family land.

See the links below for more help on the summary.

In the later part of the narrative, also, there is an area called "The Neck" where the poor blacks live.