The Langworthy Family, by Wm F Langworthy, says very little about Willard. However:

He was a Baptist, and appeared on a list of Pittsfield residents who, on Nov 1, 1789, objected to being taxed for the support of the Congregational minister.

Census Tracking:
* 1800 -Pittsfield, Berkshire Co, MA.
Note: On Jan 8, 1810, Willard Langworthy, his wife and family, were warned out of New Haven, Addison Co., Vermont.718
* 1810 - New Haven, Addison Co., Vermont
Note: Willard’s name is on a list of people with uncollected letters at the Middlebury, VT post office for Jan 1, 1813, April 1, 1814 and April 1, 1815.
* 1820 - Deerfield, Oneida Co, NY. His household contained himself, one male, 10 - 16, his wife and several daughters.

Willard doesn’t appear in any census after 1820, so the censuses do not directly supply the names of his family members. However his wife Elizabeth appears in censuses in 1850, 1855 and 1860 which, together with other records, allows us to compile a (possibly incomplete ) list. The various censuses have widely varying estimates of the children’s ages, so I’ve used averages of the later census values as an estimate.

I’ve estimated his year of death as ca1825, half way between the 1820 census, when he does appear, and the 1830 census, when he does not.