Smithfield Historic District (Jefferson County, Alabama)
Smithfield Plantation House (West Baton Rouge Parish, Louisiana)
Smithfield Public Library (Cache County, Utah)
Smithfield Road Historic District (Providence County, Rhode Island)
Smithfield Tithing Office (Cache County, Utah)
Smithland (Adams County, Mississippi)
Smithland Farm (Mason County, West Virginia)
Smiths Grove Baptist Church (Warren County, Kentucky)
Smiths Grove District (Warren County, Kentucky)
Smiths Grove Presbyterian Church (Warren County, Kentucky)
Smithson and McKay Brothers Blocks (Multnomah County, Oregon)
Smithville Historic District (Burlington County, New Jersey)
Smithville--North Scituate (Providence County, Rhode Island)
Smithwick's Creek Primitive Baptist Church (Martin County, North Carolina)
Smoketown Historic District (Jefferson County, Kentucky)
Smoketown School (Berkeley County, West Virginia)
Smoky Hollow Historic District (Leon County, Florida)
Smoky Valley Roller Mill (McPherson County, Kansas)
Smoot Theater (Wood County, West Virginia)
SMS Building (Jones County, Texas)
Smuggler's House (Bristol County, Massachusetts)
Smuggler-Union Hydroelectric Power Plant (San Miguel County, Colorado)
Smurthwaite House (Maricopa County, Arizona)
Smyrna Baptist Church (Allendale County, South Carolina)
Smyrna Elementary School (Chenango County, New York)
Smyrna Historic District (Kent County, Delaware)
Smyrna Town Hall--Opera House (Chenango County, New York)
Smyser and English Pharmacy (Philadelphia County, Pennsylvania)
Smyth Public Library (former) (Rockingham County, New Hampshire)
Smyth Young Field Company Building (Philadelphia County, Pennsylvania)
Snake Alley (Des Moines County, Iowa)
Snake Alley Historic District (Des Moines County, Iowa)
Snapp House (Jefferson County, Kentucky)
Snead Junior College Historic District (Marshall County, Alabama)
Snead Manufacturing Building (Jefferson County, Kentucky)
Snee Farm-Charles Pinckney National Historic Site (Charleston County, South Carolina)
Snellenburg's Clothing Factory (Philadelphia County, Pennsylvania)
Snider Hall (Dallas County, Texas)
Sniffen Court Historic District (New York County, New York)
Snipes-Fox House (Chatham County, North Carolina)
Snohomish Historic District (Snohomish County, Washington)
Snook House (Shelby County, Kentucky)
Snow Academy Building (Sanpete County, Utah)
Snow Camp Mutual Telephone Exchange Building (Alamance County, North Carolina)
Snow Hill (Prince George's County, Maryland)
Snow Hill (Surry County, Virginia)
Snow Hill (Bourbon County, Kentucky)
Snow Hill Colored High School (Greene County, North Carolina)
Snow Hill Historic District (Greene County, North Carolina)
Snow Hill Normal and Industrial Institute (Wilcox County, Alabama)
A historic African American school in Snow Hill, Alabama.
Snowden House (Black Hawk County, Iowa)
Snowdoun (Lowndes County, Mississippi)
Snowflake Townsite Historic District (Navajo County, Arizona)
Snowland (Kent County, Delaware)
Snyder Estate Natural Cement Historic District (Ulster County, New York)
Roughly bounded by Rondout Creek, Binnewater and Cottekill roads and Sawdust Avenue
Snyder House (Morehouse Parish, Louisiana)
Socastee Historic District (Horry County, South Carolina)
Social Circle Historic District (Walton County, Georgia)
Social Science House (Seneca County, Ohio)
Social Service Building (Philadelphia County, Pennsylvania)
Socialist Hall (Silver Bow County, Montana)
Socialist Labor Party Hall (Washington County, Vermont)
Society for the Lying-In Hospital (New York County, New York)
Society Hill Historic District (Philadelphia County, Pennsylvania)
Society Hill Historic District (Columbia County, Wisconsin)
Society of Friends Hall (Warren County, New York)
Socrates A. Myers House (Lemhi County, Idaho)
Sodality Chapel (Mobile County, Alabama)
Sofia Warehouse (New York County, New York)
Sohmer and Company Piano Factory (Queens County, New York)
Soho Cottage (Worcester County, Massachusetts)
Sojourners Club (Adair County, Missouri)
Sokol Gymnasium (Linn County, Iowa)
Sokol Pavilion (Saline County, Nebraska)
Sol Akins Farm (Bulloch County, Georgia)
Sol Loeb Building--Garrett--Joy Building (Muscogee County, Georgia)
Solar Building (Bernalillo County, New Mexico)
Solar Hill Historic District (Bristol, Virginia)
Soldani Mansion (Kay County, Oklahoma)
Soldier's Rest (Clarke County, Virginia)
Soldiers and Sailors Memorial Auditorium (Hamilton County, Tennessee)
Soldiers and Sailors Memorial Building (Wyandotte County, Kansas)
Soldiers and Sailors Memorial Coliseum (Vanderburgh County, Indiana)
Soldiers Memorial Library (Oxford County, Maine)
Soldiers' Home Historic District (Flathead County, Montana)
Solitude (Montgomery County, Virginia)
Solitude Plantation House (West Feliciana Parish, Louisiana)
Solla-Carcaba Cigar Factory (St. Johns County, Florida)
Soloman J. Strang House (Rock County, Wisconsin)
Private Residence closed to the public
Soloman Levy House (Franklin County, Ohio)
Soloman Whitmer House (Perry County, Ohio)
Solomon and Henry Weil Houses (Wayne County, North Carolina)
Solomon Fowler Mansion (Elkhart County, Indiana)
Solomon Fussell Farm (Madison County, Indiana)
Solomon Gans House (Pulaski County, Arkansas)
Solomon House (Philadelphia County, Pennsylvania)
Solomon Wilson Building (Wabash County, Indiana)
Solvay Public Library (Onondaga County, New York)
Somers Hamlet Historic District (Westchester County, New York)
Somers Historic District (Tolland County, Connecticut)
Somers Mansion (Atlantic County, New Jersey)
Somers Town House (Westchester County, New York)
Somerset (Powhatan County, Virginia)
Somerset Academy (Somerset County, Maine)
Somerset Apartments (Wayne County, Michigan)
Somerset Armory (Pulaski County, Kentucky)
Somerset County Courthouse (Somerset County, Maine)
Somerset Downtown Commercial District (Pulaski County, Kentucky)
Somerset Historic District (Perry County, Ohio)
Somerset Hotel (Cook County, Illinois)
Somerset Place State Historic Site (Washington County, North Carolina)
Somerset Roller Mills (Mercer County, New Jersey)
Somerton Historic District (Suffolk, Virginia)
Somerville (Kent County, Delaware)
Somerville City Hall (Middlesex County, Massachusetts)
Somerville Courthouse (Morgan County, Alabama)
Somerville Historic District (Fayette County, Tennessee)
Somerville Journal Building (Middlesex County, Massachusetts)
Somerville Theatre (Middlesex County, Massachusetts)
Sommerer House (St. Joseph County, Indiana)
Sommerville-Kearney House (Orleans Parish, Louisiana)
Sonner Hall (Warren County, Virginia)
Sonoma Grammar School (Sonoma County, California)
Sonoma State Home--Main Building (Sonoma County, California)
Sons of Italy Hall (St. Louis County, Minnesota)
Sons of Jacob Synagogue (Providence County, Rhode Island)
Sons of Norway Hall (Petersburg Borough, Alaska)
Soo Hotel (Burleigh County, North Dakota)
Soo Line Depot (Crow Wing County, Minnesota)
Soo Line Passenger Depot (Ward County, North Dakota)
Sooner Theater Building (Cleveland County, Oklahoma)
Sophenia Ish Baker House (Jackson County, Oregon)
Sophia Historic District (Raleigh County, West Virginia)
Sophia's Dairy (Harford County, Maryland)
Sophian Plaza (Jackson County, Missouri)
Sophie May House (Somerset County, Maine)
Sorapuru House (St. John the Baptist Parish, Louisiana)
Soren Simonsen House (Sevier County, Utah)
Sorenson House (King County, Washington)
Sorum Hotel (Perkins County, South Dakota)
Sosnik-Morris-Early Commercial Block (Forsyth County, North Carolina)
Sotcher Farmhouse (Bucks County, Pennsylvania)
Sotterley (St. Mary's County, Maryland)
Soulard-Page District (St. Louis, Missouri)
Soule, Lawrence, House (Middlesex County, Massachusetts)
Soulier House (St. Martin Parish, Louisiana)
South 9th Street Historic District (Hamilton County, Indiana)
South Amherst Common Historic District (Hampshire County, Massachusetts)
South Aspen Street Historic District (Lincoln County, North Carolina)
South Bartow Residential District (Polk County, Florida)
South Bass Island Light (Ottawa County, Ohio)
South Beach Street Historic District (Volusia County, Florida)
South Bend Brewing Association (St. Joseph County, Indiana)
South Bend Remedy Company (St. Joseph County, Indiana)
South Bend Remedy Company Building (St. Joseph County, Indiana)
South Bethlehem Downtown Historic District (Northampton County, Pennsylvania)
South Bluefield Historic District (Mercer County, West Virginia)
South Bluffs Warehouse Historic District (Shelby County, Tennessee)
South Boise Fire Station (Ada County, Idaho)
South Boston Boat Clubs Historic District (Suffolk County, Massachusetts)
South Boston Historic District (Halifax County, Virginia)
South Bottoms Historic District (Lancaster County, Nebraska)
South Branch Historic District (Somerset County, New Jersey)
South Branch Library (Milwaukee County, Wisconsin)
Former neighborhood library now used by St. Vincent DePaul
South Britain Historic District (New Haven County, Connecticut)
South Broad Street Historic District (Floyd County, Georgia)
South Broad Street Row (Iredell County, North Carolina)
South Broad--East Fifth Streets Historic District (Alamance County, North Carolina)
South Broadway Historic District (Brown County, Minnesota)
South Broadway Neighborhood District (Scott County, Kentucky)
South Brooklyn Commercial District (Cuyahoga County, Ohio)
South Camden Historic District (Camden County, New Jersey)
South Canon High School (Fremont County, Colorado)
South Capitol Neighborhood Historic District (Thurston County, Washington)
South Carolina State Armory (Richland County, South Carolina)
South Carolina State College Historic District (Orangeburg County, South Carolina)
South Carolina State Hospital, Mills Building (Richland County, South Carolina)
South Carolina Statehouse (Richland County, South Carolina)
South Carolina Western Railway Station (Darlington County, South Carolina)