Final answer:
The statement likely refers to Fort Sumter during the American Civil War, which, after a bombardment, surrendered to Confederate forces and marked the beginning of the war.
Step-by-step explanation:
The statement 'After a three-week battle, the fort gave an unconditional surrender and was taken over' seems to pertain to a specific historical event related to a fort. Without more context, it is difficult to determine the exact historical event referenced. However, the description provided aligns closely with the fall of Fort Sumter at the beginning of the American Civil War. Confederate forces bombarded Fort Sumter on April 12, 1861, and after enduring significant bombardment, the Union garrison, faced with dwindling supplies, surrendered on April 14, 1861. This marked the start of the Civil War.