Joyce Appleby, a distinguished historian and author who argued that ideas about capitalism and liberty were fundamental in shaping the identity of early Americans, died on Dec. 23 at her home in Taos, N.M. She was 87.

The cause was complications of pneumonia, her daughter, Ann Lansburgh Caylor, said.

Dr. Appleby, a former journalist who began her Ph.D. training at 32 while caring for three children, rose to the top ranks of the discipline, serving as president of the Organization of American Historians, the American Historical Association and the Society for Historians of the Early American Republic.

She wrote several books, contributed to others and edited several more; she was 84 when her final book, “Shores of Knowledge: New World Discoveries and the Scientific Imagination,” was published.

She was also a scholar of Thomas Jefferson and wrote a brief biography of him, published in 2003.

Dr. Appleby was part of a generation of historians who examined the ideologies and beliefs that animated the American Revolution. These scholars took seriously the ideas of the founding generation, breaking with Progressive Era historians like Charles A. Beard, who had dismissed revolutionary ideas as rhetorical cover for the founders’ economic interests. But the scholars were not united in their interpretation.