First graders engaged in an extended historical inquiry. Close readings of secondary and primary sources evoked rich class discussion. Scaffolding directed students' scrutiny of secondary sources for historical gaps; they ably detected source and intent within the primary sources. Students articulated newly constructed understandings through diverse forms of text-based writing. Students' verbal contributions were far more robust than written communications. They demonstrated criticality and historical thinking quite substantively during classroom discussions, small-group dialogue, or one-on-one interactions, such as when asked to clarify their written statements. Students also engaged in an age-appropriate adaptation of informed action. Limitations included lack of time available for extended inquiries and students' inexperience, which are expected considering the age group. Teachers and research can gain rich, nuanced understandings from close examinations of classroom-based learning.