Ed,
I'm not a "real flag guy" but here's my two-cents worth.
There is a flag at the South Carolina Archives "Fireproof Building" in Charleston. It is huge, sort of in the pattern of a U.S. flag except the canton is red and the stripes are blue/white. On the canton are two palmetto trees. There seems to be no one particularly preferred pattern to the palmetto on the State's flags during the war. But the trees on this flag have a peculiar design to them of which I have not observed on any other flag except the red flag in Iowa. The flag in Charleston was flown over Fort Walker during the Union attack on Beaufort, S.C. The palmetto trees on the two flags appear to be cut from the same stencil, the texture of the trunk, the frond pattern, both are so much alike that they must have been cut by the same hand. I have never observed this pattern on any other S.C. state flag. This single coincidence tells me that the red flag in Iowa can be dated to mid 1861 South Carolina.
I think there is a strong possibility of it being, if not THE legendary "big red", possibly one of the flags flown in the defense of Charleston during the U.S. invasion.
It seems that the history of this red flag is more than a little sketchy, but it had to get to Alabama someway.
It has been observed that the soldier who captured it stated that it was taken in Mobile, not Fort Blakely. Surely that is not a discrepancy. I landed in Chu-Lai in '65. I spent some time there, traveled around, and every where I went was Chu-Lai. Must've had a ten mile radius in which everything was Chu-Lai. I spent time in Danang. Well, not actually Danang. An artillery outpost about 15 miles from Danang, but I was told that I was in "Danang." I went north with my unit to Phu-Bai. Well, not exactly Phu-Bai. An little muddy hill named "Camp Carroll" or "artillery plateau." But I was more or less in Phu-Bai. Or maybe it was cloer to Dong Ha. I'm sorry. I actually am trying to make a point. The soldier's statement surely does not have to be taken so seriously specific.
I don't know if its "big red" or not but my money's on mid-1861, Charleston, S.C.
Everybody's got an opinion. Nothing's going to change.
Thanks for the post.