For Black History Month (February 2000), three U.S. Postal Service lessons help students explore the nation's differences and similarities. Students are encouraged to think about the lessons of the past and to form solutions for the future. Lesson 1, "American Diversity," looks at the overall meaning of diversity, examines ways to stop prejudice in school, and teaches tolerance and listening skills through teamwork. Lesson 2, "Messages of Freedom," explores African American history by introducing students to a diverse group of accomplished individuals who have been commemorated by the United States Postal Service on stamps. Lesson 3, "Cover Stories," highlights the Patricia Roberts Harris stamp, the most recent addition to the United States Postal Service's Black Heritage series, and teaches students a great way to collect commemorative stamps. (LB)