To the best of my knowledge, this slim volume is the only book ever written on the history of legal apologetics. William P. Broughton, a retired minister (now deceased), published the book in 2009 through Xulon Press – a print-on-demand press for self-publishing Christian books.
The book summary on the Xulon website makes the subject sound about as interesting as reading the first 10,000 digits of π, but I found the book to be accessible and informative. Although Broughton’s prose may be a bit stilted, the book provides a great deal of information.
Broughton notes that scholarly accounts of the history of Christian apologetics are few in number and they give short shrift to legal apologetics. For example, the best-known historical study of apologetics, A History of Apologetics by Avery Cardinal Dulles, does not even mention Simon Greenleaf, the father of modern legal apologetics.
Other books such as Mapping Apologetics by Brian K. Morley discuss how legal apologetics fits into the current apologetic landscape. However, if you want to read about the history of legal apologetics, Broughton is pretty much your only choice.
Broughton writes from an apologetic point of view, so he does not write a very critical analysis. Nonetheless, he forthrightly states his bias, which is the most you can expect from any apologist.