On October 17, 1865, Stokes married Helen Louisa Phelps (1846–1930).
They were related, both being descended from George Phelps (c. 1606–1687) who came to America in 1630 from  England.
Together, they were the parents of:
 Isaac Newton Phelps Stokes (1867–1944), an architect, who, in 1895, married Edith Minturn (1867–1937), daughter of shipping magnate, Robert Bowne Minturn, Jr. (1836–1889); Edith, by way of a sister, Sarah May Minturn (1865–1919) – who was married to Henry Dwight Sedgwick III (1861–1957) – was a great-aunt of actress Edie Sedgwick (née Edith Minturn Sedgwick; 1943–1971);
 Sarah Maria Phelps Stokes (1869–1943), who, in 1890, married Baron Halkett (né Hugh Colin Gustave George Halkett III; 1861–1904) (aka Baron Halkett of London and Frelsdorfermühlen, Hanover; a district next to Frelsdorf); they divorced in England in 1902; she wrote children's books under the pseudonym Aunt Sadie;
 Helen Olivia Phelps Stokes (1870–1945), who was an activist and painter;
 James Graham Phelps Stokes (1872–1960), a noted socialist, who, in 1905, married Rose Harriet Pastor (née Wieslander; 1879–1933), a social activist and feminist;
 Rev. Anson Phelps Stokes Jr. (1874–1958), an educator and clergyman; 
 Ethel Valentine Phelps Stokes (1876–1952), married philanthropist John Sherman Hoyt in 1895;
 Caroline Margaretta Phelps Stokes (1878–1964), who, in 1903, married Wiles Robert Hunter (1874–1942), sociologist and author;
 Mildred Evelyn Phelps Stokes (1881–1970), who, in 1907, married Ransom Spafard Hooker, M.D. (1873–1957);
 Harold Montrose Phelps Stokes (1887–1970), who wrote for The New York Times as a free-lance author
On August 12, 1899, Anson lost one of his legs in a horse-riding accident when he was thrown against a tree and his leg crushed.
 He had been warned that the horse, a gelding called Dingley, was dangerous but felt confident that he could handle the animal.
 After the accident a vet cared for the horse, but recommended that the horse be destroyed due to its unpredictable temperament.

Stokes died on June 29, 1913 at 230 Madison Avenue, and was survived by nine children: four sons and five daughters.
 His personal wealth was estimated at USD $25,000,000 at the time of his death, or about USD$ 646,717,172 in today's dollars.
 However, when his estate was settled, a month after his death, it was reported that the actual value of his estate was between $500,000 and $750,000 (about USD$ 19,401,515 in today's dollars.
 His widow, Helen Louisa (Phelps) Stokes survived him and died in 1930.
On October 17, 1865, Stokes married Helen Louisa Phelps (1846–1930). They were related, both being descended from George Phelps (c. 1606–1687) who came to America in 1630 from  England. Together, they were the parents of:
 Isaac Newton Phelps Stokes (1867–1944), an architect, who, in 1895, married Edith Minturn (1867–1937), daughter of shipping magnate, Robert Bowne Minturn, Jr. (1836–1889); Edith, by way of a sister, Sarah May Minturn (1865–1919) – who was married to Henry Dwight Sedgwick III (1861–1957) – was a great-aunt of actress Edie Sedgwick (née Edith Minturn Sedgwick; 1943–1971);
 Sarah Maria Phelps Stokes (1869–1943), who, in 1890, married Baron Halkett (né Hugh Colin Gustave George Halkett III; 1861–1904) (aka Baron Halkett of London and Frelsdorfermühlen, Hanover; a district next to Frelsdorf); they divorced in England in 1902; she wrote children's books under the pseudonym Aunt Sadie;
 Helen Olivia Phelps Stokes (1870–1945), who was an activist and painter;
 James Graham Phelps Stokes (1872–1960), a noted socialist, who, in 1905, married Rose Harriet Pastor (née Wieslander; 1879–1933), a social activist and feminist;
 Rev. Anson Phelps Stokes Jr. (1874–1958), an educator and clergyman; 
 Ethel Valentine Phelps Stokes (1876–1952), married philanthropist John Sherman Hoyt in 1895;
 Caroline Margaretta Phelps Stokes (1878–1964), who, in 1903, married Wiles Robert Hunter (1874–1942), sociologist and author;
 Mildred Evelyn Phelps Stokes (1881–1970), who, in 1907, married Ransom Spafard Hooker, M.D. (1873–1957);
 Harold Montrose Phelps Stokes (1887–1970), who wrote for The New York Times as a free-lance author
On August 12, 1899, Anson lost one of his legs in a horse-riding accident when he was thrown against a tree and his leg crushed.  He had been warned that the horse, a gelding called Dingley, was dangerous but felt confident that he could handle the animal.  After the accident a vet cared for the horse, but recommended that the horse be destroyed due to its unpredictable temperament.
Stokes died on June 29, 1913 at 230 Madison Avenue, and was survived by nine children: four sons and five daughters.  His personal wealth was estimated at USD $25,000,000 at the time of his death, or about USD$ 646,717,172 in today's dollars.  However, when his estate was settled, a month after his death, it was reported that the actual value of his estate was between $500,000 and $750,000 (about USD$ 19,401,515 in today's dollars.  His widow, Helen Louisa (Phelps) Stokes survived him and died in 1930.
Anson Phelps Stokes