Vermont Gov. Philip H. Hoff (D) and his wife, Joan, in 1963, in front of the Vermont State House. (AP)

Philip H. Hoff, a three-term Vermont governor credited with starting the Green Mountain State’s transition from one of the most Republican-entrenched states in the country to one of the most liberal, died April 26 at his home in Shelburne, Vt. He was 93.

The Residence at Shelburne Bay, the assisted-living center where he had been residing, announced the death. No further details were provided.

A lawyer and one-term state legislator at the time, Mr. Hoff in 1962 became the first Democrat to be elected governor of Vermont in more than 100 years as party members were beginning to make electoral inroads in the state. He came from a Republican family but modeled himself after the idealistic Democratic presidential campaign of John F. Kennedy.

He was equally telegenic and energetic, bounding around the state with a message that the state “could do a better job at everything from educating its children to improving its highway system,” according to his biographers Anthony Marro, Samuel B. Hand and Stephen C. Terry.

Soon after election, the authors noted, the governor was aghast to learn that the state budget officer had made no projections of income. “We must plan for the future, but we don’t have the knowledge on which to base a plan,” his biographers quoted him telling a colleague. “I’m just trying to find out what in hell we’ve got so we can decide what to do about it.”

At the mid-point of the 20th century, Vermont remained one of the most Republican states in the country. The state was dominated by a couple of political families, but Mr. Hoff shook up the staid Vermont political structure.

He became governor when the state was under a federal court mandate to reapportion the state House, where each of the state’s 241 cities and towns were represented by a single person, no matter the community’s population.

“The people of Vermont have clearly said that they don’t want to continue with the old ways, and if we fail to respond to forces at work in our society, we face a bleak future,” Mr. Hoff said at his 1963 inaugural address.

During his six years in office, he helped start a process that evolved into the state’s environmental movement. He focused on reducing pollution and cleaning up Vermont’s rivers and streams. He also emphasized education reform, pushed for an educational television channel and helped revamp the state’s judicial system.

The office has alternated between Democratic and Republican governors since Mr. Hoff was elected.

Philip Henderson Hoff was born in Turners Falls, Mass., on June 29, 1924. He left Williams College in Massachusetts to serve in the Navy during World War II and completed his undergraduate degree at Williams in 1948. He then earned a law degree at Cornell University in 1951 before moving to Burlington, Vt.

Mr. Hoff first ran for office in 1958 for a seat on the Burlington Board of Aldermen. He was defeated. Two years later, he was elected to the Vermont House after running what biographer Terry called “a minimalist campaign.” He had no campaign literature of his own and instead handed out brochures promoting Kennedy’s presidential candidacy.

After one term in the legislature, Mr. Hoff won the race for governor in 1962 after he campaigned on the need for change and to end 100 years of one-party rule.

Mr. Hoff ran for a U.S. Senate seat in 1970 but was trounced by incumbent Sen. Winston L. Prouty (R). Contributing to his defeat was his announcement, soon before the election, that he was a recovering alcoholic. In addition, his Vietnam War dissent and embrace of civil rights causes, including support for a summer program to bring inner-city New York kids to Vermont, was not met with universal enthusiasm by voters.

Mr. Hoff resumed his legal career and returned to politics in the 1980s by serving three terms in the state Senate.

He married Joan Brower in 1948, and they had four daughters. A complete list of survivors was not immediately available.