Now that's an odd way of reasoning. You are effectively maintaining that all the property of the general government as of 1860 on the eve of secession was in reality property of only the northern part of that government. As a result you demand that, even though the property was previously divided across the entire country prior to the split, it suddenly became the exclusive property of the north after the split and somehow needed to be "purchased" from them by the south.
Oh, and save your usual bullsh*t about the south supposedly leaching off of the north. As I have previously demonstrated to you, most of those forts that the north "claimed" as its own were bought, built, and paid for by the colony of South Carolina and later the state of South Carolina. During the period where they were under federal control, they frequently fell into disrepair and neglect so the feds obviously weren't paying much for their upkeep. And once again, the north got just as many forts built in it as the south did. Charleston got a fort built in the middle of its harbor but so did Baltimore, Philadelphia, New York, and practically every other yankee city. Want to talk about mints again? If so, show me the last time there was a gold rush in yankeeland that necessitated a branch mint, however small it may have been, to coin the new extracts from the ground. That's right. There weren't any. Yet mints were built at the location of both major pre-war gold rushes in the United States: North Carolina and California.