James McPherson has called the design of the spring campaign of 1864 a "concentration in time" ... (p. 47-48)She refers here to a recent book called Tried by War in which McPherson appropriates a term and presents it as his own. Reardon's reference helps McPherson's claim to stolen property.
We went through origins of this term in this post and in this one and in this one.
Briefly, the term belongs to Clausewitz's On War which discusses Vereinigung der Kräfte in der Zeit and Sammlung der Kräfte im Raum. Concentration in time, concentration in space, is how we render these in English. Variant translations sometimes give "unification" and "collection" vice concentration.
Hattaway and Jones introduced Clausewitz's term as concentration in time explicitly in 1986 as an aid to understanding Lincoln's orders. In 1992, Jones went hog wild with "concentration in time" in his famous Civil War Command and Strategy. It was a hallmark of the book. In both books, "concentration in time" is analyzed not only per 1864 but from 1861 onward, beginning with Lincoln's orders for advances on all fronts to take place on 2/22/1862.
Carol Reardon has read these secondary works - she mentions them, she cites them in her own book. (If she has not also read Clausewitz, shame on her.)
She has no excuse for attributing others' terms or others' insights to James McPherson.
p.s. Misattribution extends beyond Reardon but usually involves ill-read fans crediting McPherson erroneously through their own ignorance. Here there can be no such excuse.
CORRECTION (5/24/12): In an earlier version of this post, I had referred to Reardon as a student of James McPherson. This has been excised. The only known published graduate students of McPherson identified to date in this blog are Catherine Clinton and Tom Carhart.