After the Chancellorsville Campaign (April 30th- May 10th, 1863), President Jefferson Davis reluctantly gave into Lee invading Maryland which in turn lead to Gettysburg and a turning point for the American Civil War. However, what if Lee didn't invade Maryland? President Davis did try and convince Lee to help with reliving Vicksburg from General Grant. So, the Alternative History is that Lee sent his army from Virginia to Vicksburg, Mississippi in the hopes of beating Grant's army. However, there are a few concerns I have with this plan that a few historians (I forget their names) have supported. First off, Lee's army was listed around 75,000 men at the time of the Gettysburg Campaign (June 3rd - July 24th, 1863), and Hooker's army was listed at 90,000. I find it really hard to believe that Lee would shift his whole army from Virginia to Mississippi while the Union still has a large force in Maryland. Besides Lee's army, I have no idea what other Confederate forces were on the Eastern front to could help in the defense of Virginia if Hooker were to invade. I doubt that Abe Lincoln would pass would an opportunity to attack while Lee's army wasn't around. So I'm forced to conclude that Lee would have to split his army. One half would defend against a possible attack into Virginia, and another half would be sent to attack Grant's army. Grant's army during the siege of Vicksburg (May 18 – July 4, 1863) is listed at around 77,000 and Pemberton is listed around 30,000 men. Maybe combined attack of Pemberton and Lee might force Grant to retreat, and once Johnson's force joins with Pemberton, Lee can head on back to Virginia to help against any attack Hooker might launch or did launch. So far, so good, but then there is another problem. Richmond and Vicksburg are about 955 miles away from each other. Unless the army was traveling about 25 to 30 miles a day, it would be impossible to each Vicksburg before it surrendered. We can forget about transporting troops by ship because of the Union blockade, which means that the only means of reaching Vicksburg in time is the South's railroads. This link shows the railroads during the American Civil War. http://teacher.scholastic.com/activities/bhistory/underground_railroad/map.htm As you can see, only two railroads are possible: One that goes into Tennessee, northern Alabama, and then Mississippi its self. However, Corinth, Mississippi, a major railroad junction, was captured by the Union in 1862 and they are currently holding it. Which means that if they will have to stop in Northern Alabama or Southern Alabama and march the rest of the way. It would take roughly 15 to 16 days to reach Vicksburg from either location (The Train would take about 2-3 days to go from Richmond Virginia to Mississippi). In other words, by about June 5th, 1863, Robert E. Lee's army will be in Vicksburg, and he would have to stay around until early July as that is when Johnson's army was prepared to help Pemberton. If everything goes well, Lee might be back in Virginia around July 20th. In short, Lee's army goes from Virginia to Vicksburg after May 10th, and it returns around July 20th. During this time Virginia needs to hold out against any possible attack that Hooker might launch against the state while Lee is away. It is risky to leave Virginia is a weaken state, but Vicksburg was vital to the Confederacy. Although, I'm not sure who Lee would leave in command. Maybe Longstreet? I don't know. What are your thoughts on it?