William Graves was born in Salisbury, Massachusetts, on August 23, 1785, the son of Mark (1748-1802) and Abigail Green (1765-1821) Graves. By age 18, he was master of the Salem brig Henry. From 1810 to 1817, he was captain of the Newburyport brig Abigail, making regular commercial voyages between Virginia and Europe.

In 1809, Graves married Mary Ann Pike (1786-1817) of Salisbury; they had a son, William, Jr. (1811-1877). Mary Graves died in 1817; William subsequently married her sister, Susannah Pike (1791-1878), with whom he had two more sons, Alexander (1823-1869) and Edward (1831-1873), and a daughter, Ellen (1833-1882). All three sons, William, Jr. and his two half-brothers, would become successful ship masters (and, like their father, members of the Newburyport Marine Society). In the mid-1820s, Graves moved his family from Salisbury to Newburyport. From the 1820s into the 1840s Graves continued at sea, ultimately commanding at least 18 vessels; in several cases he is listed as part-owner. Graves died on May 27, 1851.

William Graves, Jr., was born in Salisbury, Massachusetts, on March 21, 1811, the son of William (1785-1851) and Mary Ann Pike (1786-1817) Graves. In the 1820s he began making voyages on his father's ships, training for a career as a master mariner. In 1834, the Salem merchants David Pingree and Emery Johnson entrusted Graves with the command of their bark Cynthia, bound for Canton, China. Graves made three voyages to China in the Cynthia (1834-1837) and six more as master of Pingree and Johnson's new and larger ship, Thomas Perkins (1837-1847). After more than a decade of near-continuous sailing in the China trade Graves found himself financially secure, and retired from the sea at age 37.

In 1837, he married Caroline Wells (1811-1838) and they had a son, William Wells (1838-1838). He built a house at 56 High Street, Newburyport, and in 1848, married his 24-year-old cousin Mary Graves Pike (1824-1903). They had five children: Mary Caroline (1849-1854); William (1850-1892); Georgiana West (1852-1934); Annie Pike (1854-1934); and Edmund P. (born 1857).

In 1849 he set up offices at 8 Ferry Wharf and with his business partner Micajah Lunt began buying substantial interests in sailing ships of the 1000-ton class, built in the shipyard of John Currier, Jr. of Newburyport. Among these vessels were Castilian (built 1849); Volant (1853); Gleaner (1854); George West (1855); Josiah L. Hale (1857); Kenmore (1861); Winona (1862); and Tennyson (1865). In addition to the Newburyport ships indicated above, Graves bought shares in several Salem vessels, including the barks Arthur Pickering and Dragon. On occasion his ships were commanded by his brothers, Alexander and Edward, or by his brother-in-law Edmund J. Pike. Apart from managing his shipping business, Graves took an active role in civic affairs in Newburyport, serving as alderman and mayor. He was also president of the Newburyport Marine Society, president of Bartlett Steam Mills, and a director of the Merchants' National Bank. He died on September 1, 1877, in Newburyport.