Moseley served in the Connecticut House of Representatives almost continuously from 1751 until he moved to Vermont, although the exact length of his service cannot be determined because his son Increase Moseley, Jr. (1740 – 1811) also served in the legislature and the rolls do not differentiate between the two.
At the start of the American Revolution Moseley was active on several committees formed to coordinate the activities of the colonists, including the Connecticut committee formed to aid Boston, Massachusetts during the British occupation at the start of the war.
In 1779 Moseley moved to Clarendon, Vermont. In 1780 he was named a Judge of the Rutland County Court, serving until 1781. In 1780, Moseley also served as an Associate Justice of the Vermont Supreme Court.
Moseley returned to the judgeship of the Rutland County Court in 1782 and served until 1787.
In 1785 Moseley served as President of Vermont's first Council of Censors, the body charged with reviewing the actions of the executive and legislative branches every seven years to ensure compliance with the Vermont Constitution.
Moseley died in Clarendon on May 12, 1795.
- Men of Vermont Illustrated, by Jacob G. Ullery, 1894, page 173
- History of Ancient Woodbury, Connecticut, by William Cothren, Volume 1, 1854, pages 385 to 386
- Historical Memoranda: With Lists of Members and Their Revolutionary Ancestors, published by Massachusetts Society, Sons of the American Revolution, 1897, page 359
- Records of the Governor and Council of the State of Vermont, published by E. P. Walton (Montpelier), Volume 3, 1875, pages 272 to 273
- Lineage Book, by Daughters of the American Revolution, Volume 44, 1917, page 171
- Early History of Vermont, by LaFayette Wilbur, Volume 3, 1902, page 345
- Genealogical Data from Colonial New Haven Newspapers, by Kenneth Scott and Rosanne Conway, 1979, page 453
- Magazine article, The Supreme Court, by Russell S. Taft, The Green Bag magazine, (December, 1893), page 564
- Vermont Archives and Records Administration (2017). "Justices of the Supreme Court, 1778 – Present" (PDF). sec.state.vt.us. Montpelier, VT: Vermont Secretary of State. p. 1.
- List of Speakers of the Vermont House of Representatives, published by Vermont Secretary of State, Archives and Records Administration, 2012
- Encyclopedia of Vermont Biography, by Prentiss Cutler Dodge, 1912, page 80
- Year Book, published by Society of Colonial Wars in the Commonwealth of Massachusetts, 1895, pages 191 to 193
- Vermont Council of Censors web page, home page, accessed March 2, 2012
- Vermont: The Green Mountain State, by Walter Hill Crockett, Volume 2, 1921, page 403
- History of Norwich, Connecticut, by Frances Manwaring Caulkins, 1866, pages 236 to 237
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