History: Primary sources, secondary sources, and bias

You read a diary entry from 1848 and a textbook chapter written last year—both are "about" the same riot, but they play different evidentiary roles. Primary sources are artefacts from the time or actors involved; secondary sources analyse, synthesise, or narrate using evidence. Good history moves between them instead of treating either as oracular.

Practical use: research papers, museum labels, and debate prep. Edge case: edited collections blur lines; you read introductions to see who selected and translated. The US National Archives primer frames document types for classrooms [1]; the Library of Congress teachers' portal links analysis routines [2].