CAPITAL INVESTED IN MANUFACTURING
By the time of the Civil War, the United States was essentially two separate and very distinct areas. The industrial, more urbanized North and the agricultural, slave owning South.
This is a common misapprehension.
No part of the 1860 United States was predominantly urban, or industrial.
The free states were more urban and more industrial than the slave states.
Whether they were "slightly" more or "considerably" more depends on how one views the difference. Suppose Algonia is 5% Protestant and 95% Catholic, while Bergovia is 10% Protestant and 90% Catholic. Bergovia is twice as Protestant ("big" difference) but only 5% more Protestant ("small" difference).
In 1860, in the eleven "Confederate" states, 1.22% of the total population were employees of industrial concerns; in the rest of the country, 5.41%. That's of the total popuiation, including children, so the proportion of the working-age population would be higher. But still only a small fraction, except in MA, RI, and CT, where the industrial employee %ages were 14% to 19%.
Comparing "cash value of farms" to "capital invested in manufacturing" shows a similar pattern. For the "Confederate" states, the numbers are $1.85B and $96M; for the other states, $4.8B and $0.9B. Thus manufacturing was concentrated in the non-slave states - but was still far less important there than agriculture. Only MA had (slightly) more manufacturing capital than farm value.