Who is Mr. Jebediah Brewster from The Mostly True Adventures of Homer P. Figg and what is their importance?

Mr. Jebediah Brewster is a wealthy man who bought property in Maine with the intention of bottling spring water, but he found a vein of gemstones that he decided to mine and sell for costume jewelry. Mr. Brewster is a Quaker and believes that fighting in a war or to protect himself is wrong, but Mr. Brewster also believes that slavery is wrong. For this reason, Mr. Brewster's home is a stop on the underground railroad that helped thousands of slaves escape to Canada before and during the Civil War.

Mr. Brewster takes Homer in when he appears on his property, despite knowing that Homer was sent there by Stink and Smelt. Mr. Brewster gives Homer the information Stink and Smelt are looking for and tells him to deal with it as he sees fit. When Homer makes the right choice, Mr. Brewster offers to adopt him. Instead, Mr. Brewster arranges for Mr. Willow to escort Homer in his search for his brother.