[PeaRidge]

"And since the tables Pea gives us in the #779 link show that 1,918 ships visited New Orleans in the 12 months prior to August 31, 1860 ( a figure that doesn't include steamboats, btw),"

If you reread the tables, the 1,918 number does include steam boats.

[Heyworth]

If you reread the tables, the 1,918 number does include steam boats.

No it doesn't. It includes steam ships, but steam boats are in the next column after the totals column for ships, barks, brigs, schooners and steam ships. For the same period, the number of steam boats is tallied at 3566, so it's obvious that they can't be included in the 1,918 number.