Prime evidence of this is Stoddard's comments on "exemption-money" in The Volcano Under the City. The city "Board of Aldermen" came together and appropriated "$2,500,000", an outlandishly high fee at the time, and even today, which would pay for the draft wavers of those called. The thought being that the mob was made up of draft protesters, and that by buying them out of their draft ticket, the mob would dispel. Perhaps, had the appropriation come out the day earlier, it would have been successful, but as it were the money feel on deaf ears. Indeed Stoddard continues, "An appropriation twice as large would have been just as futile". The crowd was no longer concerned with the draft as it's central issue, but it gave lead to the pursuit of violence and thievery.
As such I would argue that the draft calls were merely the spark that instigated a social uprising unheard of before or after in American history. It was an excuse for the disillusioned and impoverished's racial and social tensions to boil over and erupt, like a Volcano Under the City. Do you agree, or was the draft the main issue of the riot?
Jon