A Democrat in an era when the Republicans controlled all facets of Vermont's statewide politics, Haselton found success at the local level, including terms as city court judge (1878–1886), member of the Vermont House of Representatives (1886–1887), and Burlington mayor (1891 to 1894).

[2] Haselton was a Democrat,[1] and became active in Vermont politics at a time when the Republican Party was in control of every major office and every facet of state government.

[3] Despite his party affiliation, he attained success at the local level with election as Burlington's city court judge, a position he held from 1878 to 1886.

[4] Haselton was asked to leave his post following a dispute with Admiral Richard Worsam Meade, the commander of the U.S. Navy's North Atlantic Squadron.

[2] In 1908, Associate Justice James Manning Tyler retired from the state Supreme Court, and Haselton was named to fill the vacancy.

His retirement lasted less than a month, because public outcry led to Associate Justice Robert E. Healy withdrawing his request for confirmation by the Vermont General Assembly, enabling the legislature to reappoint Haselton in January 1915.

[2] Haselton was a founder and the first vice president of the Green Mountain Club, the creators of Vermont's Long Trail.

[2] Through his mother, Haselton was a descendant of John Eliot, a missionary in the Massachusetts Bay Colony who was famed as the "Apostle to the Indians".

[8] The Green Mountain Club's Haselton Trail is a hiking route from Smugglers Notch to the summit of Mount Mansfield.