This is a part of the study of history known as historiography. There are many reasons why our interpretation and understanding of the past can change.

New technologies offer access to more information. For example, digitized public records like census data, property deeds, and old newspapers make it easier to uncover details that were once hard to find.

Collaborative research can create a more complex and accurate picture of history. As research and analysis are performed over time, our body of knowledge about a subject grows.

Shifting cultural values can offer new perspectives.  Every generation views the past through its own lens, shaped by the issues and ideas of its time. As a result, new perspectives can lead to new interpretations of historical events.