Teaching young students to think critically has always been important, however, as the United States transitions to a national set of learning standards which emphasizes higher-order thinking, it becomes essential. In this quasi-experimental study we evaluate the effects of exposure to the Journeys and Destinations (J&D) unit from the William and Mary language arts curriculum on students' critical thinking, reading, and writing in general education classrooms. The unit uses advanced-reading-level literature to teach the concept of change, critical reasoning, and advanced language arts skills. Students from nine fourth and fifth grade classrooms participated in the study; three used the William and Mary language arts model, while six were asked to use their normal language arts approach. At the beginning and end of the semester students were assessed with the Bracken Test of Critical Thinking, a test of syntactic reading fluency, and a curriculum-based measure of writing. Classroom observations were used to monitor the approaches being used and assess fidelity of implementation. Results indicated that students exposed to the J&D unit grew significantly in the area of critical thinking, while the comparison group did not. Both groups grew significantly in reading, and neither group experienced gains in writing. Results are discussed in the context of professional development needs, and the move to a national curriculum focused on developing critical thinking skills in all students.