The Militia Act gives the president the power to call out the militia of the several states and insure that the laws of the United States are enforced --when Congress is not in secession.
The Court said in the Prize Cases ruling:
"All persons residing within this [rebel] territory whose property may be used to increase the revenues of the hostile power are, in this contest, liable to be treated as enemies, though not foreigners. They have cast off their allegiance and made war on their Government, and are nonetheless enemies because they are traitors."
Your position just won't stand up to the record.
Walt
Think about it Walt. If the Confederacy had cast off her allegiance to the union, to make war on "their" government would mean they were fighting themselves. If they have cast off allegiance to the US they cannot be traitors (not owing allegiance and receiving protection from the US). If still US citizens, their property is protected by the Constitution, and the government owes recompense (violation of the 5th Amendment).
The Militia Act only applies to states that are members of the Union, not foreign countries. Grier et al held the Confederacy to be a nation by virtue of application of International law.
The reason for the huge delay by Lincoln before convening Congress is contained within the Militia Act itself - "the use of militia, so to be called forth, may be continued, if necessary, until the expiration of thirty days after the commencement of the ensuing session."