How does history reflect what people were thinking at the time?

The writing of U.S. history reflects clear-cut patterns of thought at various periods. The Puritans had their Christian interpretations of history. Early colonial leaders such as William Bradford and John Winthrop reflected this approach. In the 18th century, historians stressed the Enlightenment idea that reason would guide mankind along the path of progress.

Historians in the next century turned to romantic beliefs in hero worship and adventure. Near the end of the 19th century, American historians, many of them with academic training in Germany, began to practice the teaching and writing of history as a profession. It was quite the fashion at the time to think of history writing in scientific rather than literary terms. During the Depression era of the 1930s, practically every study involved an economic interpretation.

As you can see, the way history is written is not static; it mirrors the ideas and characteristics of the time in which it was written.