In my last article I stated that Gen. Hooker set up the DEPARTMENT of military information. I was mistaken, it was a bureau. The difference is mainly money and scope.  A department would have its own resources to be autonomous of any other entity and control several other entities at the same time.  Like the Justice Department is the agency where the money for the Federal Bureau of Investigation comes from.  That's how it was originally set up anyway.

Now I had mentioned how the signal corps was an intelligence gathering agency for the Army of the Potomac (AoP). Well you need to understand something about the early signal corps.  A new battlefield communication system had been developed by a MAJ Albert J. Myer, an army surgeon in his early thirties.  He was working on communication for the deaf and blind until his experiments led him to develop in the late 1850s the aerial, or "wigwag," system for military use.  The signal corps flags you see at Brooksville.  Talk to the signal corps guys to find out how the MAJ adopted Morse code to this new way to communicate on the battlefield that no other country in the world had.  Amazing that a simple way to communicate with flags had not been used in an army before this.

Now the union was not the first to employ this system in the war.  That was the confederates that used it first. You see MAJ Myer had an apprentice.  This apprentice was none other than a young CPT E Porter Alexander.  Yes the man that on a July day in 1863  commanded all of the Confederate artillery at Gettysburg.  Alexander at First Bull Run had in place a small signal corps and was sending messages and helping to move the army.

Now both sides had a similar signal corps using similar systems of codes.  This and the fact that the signal corps had to set up stations for their flag men and observers so they needed to scout ahead.  So they were good eyes immediately ahead to the army on terrain and possible enemy positions. They would also read the other sides messages and report that to headquarters.  Sometimes on the Union side (which is the side I have read the most on right now) they would send false messages to be intercepted and acted upon by the Confederate forces.  Such as Chancellorsville where a false message was crafted by GEN Butterfield (yes the guy who wrote taps) to lure confederate cavalry out of position so GEN Hooker could flank the confederate line in a gap found by a farmer spy.

For further reading on this subject I recommend "The Secret War for the Union" by Edwin C. Fishel published by Mariner Books. What makes this book stand out is the guy found a roomful of reports in the national archives in 1959 and incorporated other items. The real kicker is the author served thirty years in intelligence starting in World War II to include Chief Intelligence Officer at the National Security Agency and also director of National Cryptologic School Press.