Constructed in 1824, the John T. Williston House is among the oldest buildings in Miramichi. It provides a good example of the Georgian architecture favored by the wealthy at the time, being a sandstone rectangular massing topped with a hipped roof.

The building was first used as a residence by John T. Williston, a prominent lawyer and businessman. Williston had a rather intense political career and was one of the main parties in the notorious "Fighting Election of 1843." In 1842, Williston joined the House of Assembly political ballot. He won, but his victory was soon voided because of allegations that his party had unfairly used intimidation to influence the election process. At the subsequent by-election in 1843, political tensions flared between him and his rival, John Ambrose Street of Newcastle, as well as between their supports. Eventually, a riot broke out amongst the voters. During the brawl, local tavern owner James Ryan was killed by a thrown rock, and reportedly as many as forty more people were injured. In the end, Williston lost the by-election but was able to secure the seat of Deputy Treasurer of Customs for the Legislative Assembly of New Brunswick in 1850. After losing that position in 1854, Williston was appointed Deputy Treasurer of Customs and remained as such until his passing in 1865. 

Following Williston's death, the Crown purchased and renovated the property in 1872. They converted the building into a customs house, post office, and Dominion Savings Bank in one. It gradually fell into a period of neglect, only to be restored again in 1982 when a group of citizens petitioned the government to fix the property. In the present, it has been converted into O'Donaghue's Irish Pub.