In what way was Petersburg a crucial victory for the Union in the civil war

The siege of Petersburg was 10 moths long and arduous as both sides had it rough. The forces of the Confederate were dug deep in the long trenches making this an extremely difficult battle but it also made the Union victory that much important as it made general Lee go into hiding and after winning this battle the Union managed to secure an important Confederate town Richmond. This all paved way for the end of the Civil War.