Here's a link I was trying to remember before that's worth reading:
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Joseph S. Bermudez Jr.
View this document as a PDF file (255k).
Copyright © Joseph S. Bermudez Jr., 1999.
Foreword
Introduction
Early Developments, 1960-1979
First Ballistic Missiles, 1979-1989
Longer Range Designs, 1989-Present
Conclusion (and Notes)