Before about 1850-1860, the farm was owned by John Warren Swezey.  The Swezey homestead was situated at 331 Beaver Dam Road (modern address, Site ID Br18A).
The preceding information was erroneous and corrected below.

A careful reading of the relevant deeds indicates that Richard Corwin [ii] owned the farm lot prior to 1857.  Deeds indicating ownership prior to Richard Corwin have not yet been found.

On 25 June 1857,  for $850,  John Warren Swezey conveyed to William Egbert Swezey (his brother) about five acres bounded on the south by Beaver Dam road (modern designation), west by George Burnett (formerly of Henry W Titus), north by Richard Corwin, and east by the heirs of Joseph Rose (ie., William Brewster Rose and John Smith Rose)— therefore clearly indicating that Richard Corwin owned the property in 1857 (Suffolk County Deeds Liber 94, page 247).

(This property would have been the southern portion of the tract that would eventually became Locust Road.  At the time of the sale, as indicated on the 1858 Chace map, there was apparently only one structure on the site, the "Swezey-DeHond House,"  Site ID 32A, then fronting on Beaver Dam road and labeled "W. Swezey.") 

On 14  August 1886, for $1300, William Hampton Corwin (Richard's son) and Martha Jane Corwin his wife conveyed  to Chauncey E. Swezey (William Egbert Swezey's son) about ten acres being the homestead of  the late Richard Corwin, bounded on the west and north by George W. Burnett, east by William Brewster Rose, and south by William Egbert Swezey—clearly this site, the Richard Corwin farm lot (Suffolk County Deeds Liber 297, page 391.)

This farm house was perhaps built by Richard Corwin sometime between about 1858 and 1860. Richard's first wife Prudence died in 1849. His neighbors in the 1850 census are suggestive that he was still living on the Corwin farmstead along South Country Road (south of the present Long Island Rail Road), most like in the original Richard Corwin (i) homestead at 408 South Country Road (Brookhaven/South Haven Historic Site ID Br05B).  The 1858 Chace map labels this South Country road house "R. Corwin."   By 1860 he has remarried Eliza, and his neighbors in the 1860 census are strongly suggestive that he is living on the farmstead and at this residence.  While no historical evidence has yet been found to suggest that the house existed prior to the Richard Corwin tenancy, some have suggested that the house may have been built somewhat earlier in the 19th century, before the Richard's occupancy.  One source indicate it was built by Sylvestor Corwin, Richard's eldest son (see "History of Locust Road).  However, the 1858 Chace map does not show the house, suggesting that it was built by Richard Corwin between 1858 and 1860.

Richard Corwin Jr. called this property  his "homestead" when he deeded the property to his son William Hampton Corwin, in May 1881.

While a 1938 article in the the Patchogue Advance indicated that William Egbert Swezey presented the property to his son, Chauncey, as a wedding present in 1888, the public record suggests otherwise;  Chauncey purchased it of Hampton Corwin in 1886 (see above).

From the Patchogue Advance, 3 June 1938: "Mr. [Chauncey] Swezey's father, William Egbert Swezey, presented the couple [Chauncey Swezey and Minnie Hulse, at their marriage in 1888] with a house which he had bought from Hampton Corwin and which stood well back from Beaver Dam road. The only entrance to the property was a 12-foot right-of-way along the east side of the Burnett property. …. See Chauncey Swezey for full transcript of article. 

From the Long Island Advance, 3 Aug 2006, From the Archives of the Long Island Advance - 50 Years Ago: "The home of Mr. And Mrs. Robert Englehardt of Locust Road has been sold to Mr. And Mrs. Irving Cantor of Brooklyn. The house, generally known as the Chauncey Swezey house, is one of the older houses in Brookhaven, it is said."

Now (2011) the house is owned by Donald and Regina David.