Nightly slave patrols had been a regular feature of Southern life since the early 19th century, perhaps even back to colonial days. You can easily find patrol regulations as part of the militia code in any Southern state. However, up until Harpers Ferry, the militia in most Southern states had fallen into disuse. In Alabama for instance, Governor Winston proclaimed the existing system “obsolete” by virtue of public indifference. Governor A. B. Moore had later derided the state militia as “a matter of ridicule, unworthy of the name of an organization.”

You're right about events in Kansas during 1856-57. They had quite an impact outside the territory. Citizens across the country began to debate whether or not a territorial legislature had the authority to outlaw slavery inside their own borders, and everyone remembered "Osawatomie" Brown for the murders of Southerners men.
http://www.kshs.org/places/johnbrown/index.htm

For a modern historical parallel, consider events leading up to 9-11:
the bombing of the World Trade Center, Feb. 26, 1993,
* http://www.fbi.gov/page2/feb08/tradebom_022608.html

* attacks on the U.S. embassies in Nairobi, Tanzania and Dar es Salaam, Aug. 7, 1998,
http://en.wikipedia.org/wiki/1998_United_States_embassy_bombings

* the attack on the destroyer, U.S.S. Cole, Oct. 12, 2000.
http://www.al-bab.com/yemen/cole1.htm

We all were aware of these events, but they didn't really concern most of us. People didn't really connnect the dots until the morning of Sept. 11, 2001.

The same is true of Harpers Ferry, which convinced Southerners that abolitionists weren't making idle threats. Like the terrorists who orchestrated the 9-11 attacks, John Brown and others abolitionists viewed slaveholders as sinners worthy only of death. Sympathy throughout the North for Brown and others involved in the Harpers Ferry conspiracy shocked the Southern public even more than the attack itself. Furthermore, documents found in Brown's Maryland hideout connected him with wealthy and influential New Englanders who had purchased cases of Sharps rifles and Colts revolvers for him.

Here are a few examples from Alabama newspapers --
The “insurrectionary demonstration at Harper’s Ferry”, noted the Florence Gazette, had evoked “a vast – almost unlimited – amount of excitement." From late October through the end of December 1859, articles related to John Brown and Harpers Ferry regularly appeared in the press. The editor of the Moulton Democrat warned his readers that adherents of the abolitionist movement intended to “devastate our peaceful homes and massacre our families.” The Benton Weekly Herald asked, “From whence came the money to buy these things?” “So large a sum… furnished for the pillage of our property and the murder of our persons, will give some idea of what the South may expect ere the ‘irrepressible conflict’ just begun is finally ended.”

Here's another article from an Alabama newspaper raising questions about purchases of weapons for the terrorists --

WHO PAID THE EXPENSES? – The chief of the Harper’s Ferry Insurrection, Brown, we believe, is not understood to be a man of much wealth. He probably had means enough to support himself comfortably in life, but he certainly had not the wealth necessary to put an army of fifteen hundred men on war footing. We say “fifteen hundred” because that is his own statement. Among his inventory we see are:

Two Hundred Sharps Rifles

Two Hundred Revolvers

One Thousand Spears

And Plenty of Ammunition

A good rifle costs about $25. We think that was above the quotation at the New Haven Church meeting. Two hundred of them would make a bill of $5,000. Two hundred revolvers, at the New York average price – say $15 each – would make $3,000 more. The “spears” is a new instrument of death, we believe in this country, but as a “spiker” to be worth anything, ought to be worth at least $5, one thousand of them adds another $5,000 to the bill. Total (without the ammunition) $13,000. Until it can be proved that Brown had that much money in cash, the inference remains that there must be some outside contributors somewhere. Now, the question is, who are the contributors? Time and enquiry will tell.

Joe, I'm sure you could find the same kind of articles in Texas newspapers from October through December of 1859.