Bill has had a strong resentment toward Frank Gallagher since the day he started hooking up with Monica, even blaming him entirely for her suffering before her death.
When it comes to his grandchildren, Bill was never in their lives and couldn't really talk to them. He was disappointed to learn Debbie was a teen mother and that the oldest ones resented Monica. However, he was proud Carl had enrolled in military school and told him to consider the navy to help his future.
Bill was a career Navy officer with forty years of service. Upon leaving the service he became a contractor and started up his own business Darrgen Sheet Metal Fabricators in Indiana. He married and had a daughter named Monica. When his daughter started getting involved with Frank Gallagher, he resented his daughter's decision as well as Frank for being a negative influence on her. Because of this, he never had any close relationships with his own grandchildren.
Upon Monica's death in Requiem For a Slut, Fiona calls up Bill's workplace to inform him of his daughter's passing. She doesn't get a hold of him so she leaves him a message. At home, the family discusses what to do with the meth Monica left behind until they hear a knock on the door. Everyone scatters and Frank attempts to hide the meth in Franny’s crib. Fiona answers the door and sees it’s Bill, who storms in and immediately goes after Frank.
Bill, blaming Frank for Monica's death, beats him up and throws him down the stairs, after which he lands a few more punches and Frank fights back. After the fight, the older Gallaghers introduce Bill to their younger siblings. Everyone gathers around the table to discuss Monica’s death, with Bill denouncing that she suffered when married to Frank. The topic shifts to the funeral, as Fiona states they didn’t have money to do anything special for her, but Bill insists he'll pay for everything to give her a proper burial. He talks with his grandchildren and things are awkward, since he was never there for them and they know nothing of him. He soon notices and comments positively on Carl's military school uniform and recommends to his grandson that he should join the U.S. Navy like he did, as it was the best choice, something that gets a smile from Carl. He then notices his great-granddaughter Frances Gallagher and commenting negatively on Debbie having a daughter at sixteen. He leaves the house to make the arrangements for the funeral, and also because he doesn't trust himself sleeping under the same roof as Frank.
At Monica's funeral, he shares a few words about his daughter. He was somewhat moved by Frank's speech about his daughter and watched as the latter left. Bill took one last look at his daughter before leaving. He went back to the Gallagher House, where he watched the family enjoy themselves while sitting down.
- Due to his lack of presence in their lives, the Gallaghers did not like him much with Fiona and Lip even insulting him.
- He has made no further appearances so far.
- Bill is the only remaining grandparent the Gallaghers have.
- Unlike Peggy Gallagher, Bill was alive to see his great-granddaughter.
- He has not yet met his great grandchildren Freddie Gallagher and Carl's unnamed kids.