In this article, the author describes her use of direct instruction to introduce the skill of determining source reliability in a fifth-grade unit on immigration in American history. She structures instruction to help students establish a thinking-skill strategy that results in not only an understanding of immigration in the late 1800s to early 1900s, but also a skill that can be used in their daily lives. This step-by-step example of direct skill instruction presents samples of student and teacher dialogue, sample historical sources, a thinking-strategy map, graphic organizers, and a written assessment. The author concludes by describing a brief student summary of what students learned about immigration and the skill, and she notes where additional scaffolded skill instruction and practice should be used in subsequent units of the course. (Contains 3 figures.)