Union forces soon captured Mobile Bay and Atlanta and now controlled the Shenandoah Valley, ensuring Lincoln's reelection in November. Sherman convinced Grant and Lincoln to send his army to march on Savannah. Sherman cut a 60-mile path of destruction unopposed, reached the Atlantic Ocean, and captured Savannah on December 22. On December 16, after much prodding by Grant, the Union Army under Thomas smashed John Bell Hood's Confederate Army at Nashville. These campaigns left Lee's forces at Petersburg as the only significant obstacle remaining to Union victory.