To determine how topical coverage in introductory textbooks may have changed from the 1980s to the present, the author examined topic coverage in full-length and brief introductory textbooks from this time period. Because 98% of the teachers use textbooks for the introductory course and the majority do not assign reading beyond the textbook, the relationship between the current topical allocation pattern and that in the introductory course was examined by comparing the textbook pattern to the lecture topical allocation pattern derived from syllabi analysis. Several changes were found in textbook topic coverage since the 1980s, with proportional coverage among topics moving toward equality. Lecture topical allocation mirrored that in textbooks, indicating that textbooks strongly impact the structure of the introductory course.