When was the town founded and by whom?
Settlers first appeared in the area now known as Lewisboro around 1720. According to legend, the first men to actually live in the area were William Truesdale and Samuel Tuttle. The men bought land from the Ridgefield Proprietors and headed west over the mountain ridge that separates the two towns. They attempted to tame the wilderness, which proved to be too difficult a task. According to the story, the two were killed by Indians and not a trace was left except the name Truesdale, which now graces a lake in the general vicinity of their land purchases.

235. Jesse Truesdell

(Source: Carla Parrish):
Had extended service as an officer in the Westchester Militia. He waschosen 1st Lieut of the Middle Battalion from the northern district ofSalem, the commission issued September 13, 1775 (Council Aptmts, NY Hist.Soc., 1925, 159). Due to "certain non-acceptances" the Chairman of theCounty reported that Jesse was chosen Captain, November 17, 1775, andrequested early issuance of this commission (Calendar, NY Hist Doc, I,205). In 1777 his company, in Col. Thomas Thomas' Regt of Westchestermilitia, consisted of: 1 Capt, 2 Lieut, 1 Bens, 3 Sgts, 1 drummer and 32Pvt, and received £258 16 2 for service at various times between Augustand December 1777 (NY State Lib "Payroll" audited in Philadelphia 1786).On May 28, 1778 he was appointed Captain to command the North Salem Co.He served at various times as a Captain in 3d Regt. and in 4th Regt.under Col. Crane, his name being on the State Treasurer's pay books,between March 1779 and November 1781. He was a Major in 2d Regt., April12, 1782. After the war, as "Trusdal" he was appointed First Major, June24, 1786, under LtCol John Hyatt and a successor was announced to hisvacancy March 25, 1787 (Council Aptmts 80).
In 1779, with others, he united to form a Congregational Church at Salemand was on the committee "to get preaching" (Hist Westchester Co., ScharfII, 523). On various occasions Rev. Silas Constant, pastor of thePresbyterian Church at Yorktown, NY stayed at Jesse Truesdell's home. In1790, living in North Salem, his family consisted of six. He wasadmitted as a freeman in 1805, first taxed in 1813, last in 1815. Hejoined the Danbury Church, June 03, 1810 on recommendation from the Ridgefield Church.
Following the Revolution Jesse Truesdell was a member of a Committee todispose of properties held by convicted Tories (Westchester Deeds, L290.Also NYGBR LXXI 277). In this manner he acquired the lands of Benjamin Close in North Salem. His home, still standing, is near Truesdale Lake, now in the hands of a real estate corporation.