During the American Civil War, Washington DC was extremely close to the confederate border, making it relatively easy for the confederacy to capture (they of course never succeeded in doing so, but still, the risk was significant), which would have significantly weakened the US' abilities to plan and organize the war effort. So, why didn't the USA just temporarily move all that important government stuff to somewhere where the confederacy couldn't capture it so easily? Sure, it would have been a logistical effort, but wouldn't it have been worth it, since it would have minimized said risk?
Edit: the same applies to the confederacy; why did they put their capital so close to the union border?
The real question is why did the Confederacy put their capitol, Richmond, so close to Washington City (it was not known as D.C. then)? Lincoln and the Union had every reason to believe that their city would remain safe if properly defended (something Lincoln always remained insistent upon until Grant convinced him otherwise). I wrote about this topic at length last year (link below), but would be happy to answer any follow up questions.
https://www.reddit.com/r/AskHistorians/comments/c2xvbc/why_did_the_government_stay_in_washington_dc/
In summary, the major reason is because DC wasn’t really at risk of being overrun.
In the first few weeks of the war, it was quite precarious. Washington DC was highly exposed and was at risk of being seized by the Confederates who amassed thousands of militias members right across the river. But it turned out the Confederates were disorganised and poorly equipped. In the first few months of the war, Northern troops arrived and fortified the city with heavy defensive works. A network of forts and tens of thousands of troops protected DC throughout the war.
In the Civil War, the attacking force had a major disadvantage against the defending force. This was driven by the accuracy and effective ranges of the rifles used by the armies. But secondarily bolstered by effective fortifications that protected the defender. The rough rule of thumb is that it took around three or so attackers to overcome each entrenched defenders.
So, with tens of thousands of troops defending DC in well fortified entrenchments, the Confederacy would have required many more men than they had available in the eastern theater of their army.
The other thing to consider is that Lincoln was extraordinary politically and diplomatically astute. His character was to do his duty despite threats on his own life. He often exposed himself to danger. He saw it as an important thing for the federal government to project strength over the rebels. He would be well aware that if DC was evacuated and overrun, then England and France would have been much more likely to recognise Confederate independence and intervene. Very often that recognition was fairly close and this is the type of political or military event that easily could have tipped the scales.
Hey there,
Just to let you know, your question is fine, and we're letting it stand. However, you should be aware that questions framed as 'Why didn't X do Y' relatively often don't get an answer that meets our standards (in our experience as moderators). There are a few reasons for this. Firstly, it often can be difficult to prove the counterfactual: historians know much more about what happened than what might have happened. Secondly, 'why didn't X do Y' questions are sometimes phrased in an ahistorical way. It's worth remembering that people in the past couldn't see into the future, and they generally didn't have all the information we now have about their situations; things that look obvious now didn't necessarily look that way at the time.
If you end up not getting a response after a day or two, consider asking a new question focusing instead on why what happened did happen (rather than why what didn't happen didn't happen) - this kind of question is more likely to get a response in our experience. Hope this helps!