FREE blacks DID NOT escape to the north (MANY free blacks WERE also SLAVEOWNERS! the damnyankees didn't tell you that in school did they?). and FEW slaves did escape-over 120 years the estimates are <20K, this from the author of RED OVER BLACK.
you really should READ my posts more carefully, as it is difficult to respond intelligently to BUNKUM!
If your figures are correct and so few slaves actually escaped up north - less that 167 per year according to your post - then why such a fuss about forcing through the Fugitive Slave Act of 1850? That means that 99.99479% of all slaves down south in 1850 did not run away up north. Why the need for legislation to deal with the remaining .00521%? Seems like a lot of time, trouble and expense for such a small problem.