Question of the Week: What was the biggest contributor to Fort Donelson falling?
164 years ago today, the Confederate army at Fort Donelson surrendered to Grant. In your view, what was the single most important factor leading to the Confederacy’s defeat there?

Utterly divided and inept Confederate leadership led to the loss of their garrison. But the Fort itself would have inevitably fallen to siege, given the Union control of surrounding river systems.
The Confederate command was structured in a dysfunctional manner that failed to coordinate and cooperate forces. The Confederate senior officers did not have personal or professional relationships to cooperate forces the good of the Confederate forces.
The union army
A weak and inept defense, a divided Confederate command structure.
I would pick Confederate leadership (or lack thereof). Grant got lucky; the Confederate leadership did not.
Albert Sydney Johnston for the decisions he made with regard to both forts (Henry & Donelson), siting – original decision made by others but he kept them there – and commanders.
As an aside, since we are in our America 250 celebration year, anyone see any comparisons between the loss of Forts Henry & Donelson and the 1776 disastrous loss of Forts Washington & Lee?
Clearly Grant’s leadership vs the Confederate command structure & inept leadership
Clearly Grant’s aggressive leadership vs the Confederate command structure & inept rebel leaders
Albert Sidney Johnston’s very late recognition of the serious threat to this defensive line that a Union attack down the Tennessee and Cumberland represented.
Someone said it already. It was because of the Union army. ‘Nough said!
Two: Floyd and Pillow
Confederate command had problems. Two generals were to busy trying to save themselves
Grant’s coup d’oeil; he saw an opening and took it.
I agree with all the comments posted! I will be gentle and say the south had there boots on the wrong feet for sure !NBF took all and left so to speak! Grant had 2 things that would elevate Grant and even save him . When Grant had the support , supplys , reinforcements ie resources he was very capable and he can thank General Sherman his superior for keeping him supplied! There relationship forged on and Sherman saved him at shilo . Albert Sidney Johnston had not been killed his comment will water are horses in the Tennessee tonight would been spot on ! The north found Grant and Sherman . They split the south in too! 1 year later The last hope for the south was Chancellorsville and Jackson getting to the the United States Ford and cutting the federals off . Jackson new . So did Lee . Grant and Sherman made the south Pay dearly! That’s How important Fort Donelson was . Grant was relentless But it’s Sherman the south remembers to this day !