Taking Independence

Taking Independence is a quest and achievement/trophy in Fallout 4.

Quick walkthrough
You must assist three settlements before Preston Garvey will approach you with this quest. He asks you to meet him at The Castle (Fort Independence) which was previously taken from the Minutemen. Upon meeting Preston and three Minutemen at an old run down store near Fort Independence, you go through some dialogue with Preston and the others before being prompted to choose a plan of attack (there are three options). After choosing one of the plans of attack, the others get into position before you engage the Mirelurks inside the courtyard of Fort Independence. After clearing Fort Independence of the Mirelurks, Preston asks that you clear the area of any egg nests. While you are clearing the eggs, the Mirelurk Queen spawns and you must defeat her. Once you have defeated her, you are to clear the area of any remaining eggs, then meet the Minutemen in the middle of the courtyard where the radio transmitter is located. After searching the workshop within the Fort, you are to provide power to the radio transmitter. (Note: The radio transmitter requires 10 power.) Afterwards, talk to Preston Garvey and the quest is completed.

Bugs

 * Companion Preston Garvey will follow you around the whole game if you start, but don't finish the quest. However you will be unable to speak or interact with him. This essentially gives you 2 companions.