High Watch was built with oil money. Plus see the end bit - Emphasis mine.

High Watch

The house was built in 1929–1930 for the Snowden family, owners of an oil company, who named it Holiday House. It was purchased in 1948 by Rebekah Harkness, socialite and Standard Oil heiress, who became notorious amongst the local residents for her lavish lifestyle there. In 1974, businessman Gurdon B. Wattles purchased and renovated the house, renaming it as High Watch due to its location.

Swift purchased the house for US$17,750,000 in 2013, and in 2020, inspired by its history and Harkness, released the song "The Last Great American Dynasty" which tells a story loosely based on Rebekah’s life. Several stalking, trespassing, and home invasion incidents have been reported at the house since Swift's purchase.

In 2015, High Watch inspired a proposal by the then-Governor of Rhode Island, Gina Raimondo, to impose a luxury tax on expensive secondary homes in the state but was quickly withdrawn following criticism that claimed such a tax would be detrimental to the state's tourism industry.

In 2017, Swift was sued by her neighbors over her decision to build a seawall on the beach as plaintiffs argued the beach had been dedicated to the public over the years and Swift had no ownership of it; the courts ruled in Swift's favor, asserting the seawall prevents coastal erosion.