Halliday-Resnick Plus 50

Last year marked the 50th anniversary of the publication of Halliday and Resnick's classic introductory textbook ``Physics.'' I used the first edition of the the textbook as an undergraduate students, the second editions as a graduate teaching assistant, the the third edition as a newly hired assistant professor, and I became a co-author for the fourth and fifth editions. In this talk I will offer some views of how this book came to re-define the introductory physics course and how this textbook and other introductory physics texts have changed over 50 years.