Hi Tom,

I have Grace Rogers Cooper's report and have read it. Really informative stuff. For those that want to read it this is available online.

From what I can find mercerized threads don't really hit the USA until after the Civil War. Europe was WAY ahead of us in that regard. Clark, for example, was Scottish. Everything I have found about Clark's 3/2 cabled thread was that it was invented before the Civil War but does not show up in the USA until 1866 at the soonest.

John Mercer indeed came up with the mercerized process of chemical treatments of cotton threads in 1844 and he sold his patents to a French company who was making it in the 1850s (and still do it seems based on what I can find). But this was for cotton threads and the flags were almost sewn entirely with linen threads that were not mercerized.

What seems to be hard to find is exactly when true chemically treated mercerized thread made its way to the USA. New England mills used a process that did not include chemicals but used, instead, a humidifier process. My friend who has dealt with CS flags for nearly 30 years has never seen mercerized cotton threads on them and, according to his work with them, almost all are linen S-twist.

The Clark 3/2 cabled thread and the mercerization process were both designed to make it easier for the threads to be used in sewing machines, but with the South cut off early by the blockade and seemingly neither process was in wide spread use in the USA before the war, they had to go with what they had; older threads.

Greg Biggs