The Wentworth–Grinnan House was built as a 1+1⁄2-story house before 1760 and was expanded with addition of a larger wing, two-and-a-half stories tall, between 1820 and 1822. The original section "has a gabled roof with dormers, clapboarding, and a brick end wall with a brick chimney stack"; the addition has "clapboarding, and a brick chimney, six-over-six sash windows, and a first-floor porch across the facade."[2] It is an example of Georgian architecture.[3]
The property was first sold in 1752 to Captain Samuel Browne for four pounds, six shillings. Browne was one of Smithfield's earliest settlers and was a sea-going man in the shipping and trading business. When he died in 1760, he was half-owner of the sloop London and his other property contained in his warehouse (located in the old dormer end of the property) included 10 barrels of coffee, 6 hogsheads and one tierce of molasses (700 gallons), 2 hogsheads of sugar, 2 1/2 tierces of rum (150 gallons), 300 bushels of salt, 50 bushels of wheat, 50 hams and bacon, and 18 pounds of allspice.[4]
Upon Browne's death the property passed to Captain Samuel Wentworth who lived on the adjacent lot and was subsequently owned by Wentworth descendants until 1809. The property later passed to a series of prominent Smithfield families and was home to the Grinnan family for 72 years.[4]
It was listed on the National Register as a contributing building in the Smithfield Historic District in 1973.[1]