The main sources of historical reconstruction are classified as:

Historians reconstructing the past draw their evidence from records of the activities that societies actually engaged in and documented over time. Two of the domains of human activity that leave the most consistent and widely used trail of evidence are governance and the economy.

Political sources cover the records generated by the exercise of authority and power within a society: king lists, treaties, accounts of wars and conquests, chieftaincy records, and administrative correspondence. Economic sources cover the records generated by production, trade, and exchange: tax registers, records of trade routes and traded goods, currency and units of exchange, and accounts of farming or craft production. Because political authority and economic activity are two of the most consistently recorded and best-preserved aspects of any society's history, classifying the main sources of historical reconstruction around these two domains gives historians a structured way to organise the surviving evidence about how a people were governed and how they sustained themselves.

External and internal sources, and primary and secondary sources, describe how close a source is to the origin of the society being studied or to the event itself, which is a different kind of classification from the subject-matter grouping the question is asking about. Scientific and religious sources likewise describe the discipline or belief system a source comes from, not the two dominant fields of human activity, governance and the economy, that the question is testing.

When a question asks how historical sources are classified, be careful to identify whether it is asking about the subject matter the sources record, such as political and economic activity, or about the source's proximity to the event, since both are valid but distinct classification systems.