One of the seminal works for the study of modern conservatism in America. It is also written in an accessible fashion for undergraduate students and is affordable to purchase. I would use parts of this book in my Introduction to Political Science or Political Thought Course and the entire book for a Political Ideologies course under the study of conservatism.
One recommendation when using this book in the classroom is to assign the primary texts along with the chapters that Kirk covers. For example, you could assign Calhoun's Union and Liberty when reading the chapter on Southern Conservatism. The only limitation I find in the work is that it ends in the 1950s (when it was published), so the study of post-1950 conservatism in America is not touched, e.g., neo-conservatism. Nonetheless, a terrific book to use in the classroom, whether in parts or in its entirety.