It should also be noted that (contrary to the impression that the other review gives) this book is no shill for the Confederate cause either. As a political scientist with a focus on finance capital, Bensel does not view the Civil War through the lens of a noble crusade to abolish slavery. At the same time, however, he uses the same lens of political economy to look at the southern state-building as well.
Ironically, the "Dixie Leviathan" was even more powerful and autonomous than the Yankee one. The small size of the southern economy and the broad popularity of the war gave the Confederate government both the need and the ability to confiscate property and trample states rights far more effectively than the Republicans did in the Union. The old slogans of Jeffersonian small government disappeared and big-government national mobilization became Dixie's order of the day. (emphasis added)
So what were saying about 18 vs 13?
http://www.amazon.com/gp/product/customer-reviews/0521398177/ref=dp_nav_0/102-3176425-4398506?%5Fencoding=UTF8&n=283155&s=books
In fact, Bensel conducts a thorough analysis of statist vote positions in the confederate versus union congresses, ranking them on a "statist" score of 0 to 100, 100 being the most pro-government. 30% of the Northern Congress scored between 90 and 100 on their statist vote patterns as opposed to only 2% of the confederate congress. Another 17% in the north scored between 80 and 90 as opposed to only 4% in the south. The south by contrast exceeded the north in the middle third of the scale due largely to the lopsided northern support for statist positions in votes (as in 47% of the yankee congress rating above 80)