Bragg's army appeared to have the Union force trapped, but the siege also fixed Confederate troops around Chattanooga. The Union could exploit its larger manpower and transport system to move Hooker's and Sherman's corps toward the same point. Confederate forces at the far end of their own supply lines therefore faced an opponent whose strength would continue to grow. A smaller besieging army can lose the initiative when it cannot finish the operation before relief arrives.
Notable Point · 29:39-31:05
The siege fixed Bragg in place while Union strength grew
Besieging Chattanooga tied down the smaller Confederate army while the Union used its larger resources to send commanders and fresh corps into the theater.