William Thaw, Sr. (October 12, 1818 – August 17, 1889) was an American businessman who made his fortune in transportation and banking.
He was born in Pittsburgh, Pennsylvania on October 12, 1818 to Mary C. and John Thaw. He worked as a clerk in his father's United States Bank of Philadelphia in Pittsburgh. He later switched to McKee, Clark and Co.
In 1841, William Thaw married Eliza Burd Blair (died 1863). They had five children that survived childhood:
1. Eliza Thaw,William and Eliza B Thaw, (1st gen) 1st daughter Eliza married George B.Edwards, (2nd gen) their daughter Burd Blair married Charles E. Dickson, (3rd gen.) their daughter Burd Blair married Frederick J. Stevenson Sr., (4th gen) their son Frederick J Stevenson Jr. married Sally Wheat, (5th gen) their son Frederick J. Stevenson III married Elizabeth Tarasi,Esq., (6th gen) they had two sons, Frederick J Stevenson IV (5/18/1990)and Benjamin Wheat Stevenson(12/2/1992). wife of George B. Edwards
2. William Thaw, Jr.
3. Mary Thaw, wife of William R. Thompson
4. Benjamin Thaw, Sr.
5. Alexander Thaw
By 1842, he and his brother-in-law Thomas Shields Clarke owned steam canal boats, particularly the Pennsylvania and Ohio line. Their company added canal, portage railroad and other steamboat lines.
With the rise of the railroad, Thaw divested the canal business and invested in the new Pennsylvania Company, which managed interests of the Pennsylvania Railroad, in which he was a large shareholder.
In 1863 after the death of his first wife, he married Mary Sibbet Copley. They had five children that survived childhood:
1. Harry Kendall Thaw (1871–1947), who would later murder Stanford White He left $10,000, less than 1% of his fortune, to Evelyn Nesbit in his will.
2. Edward Thaw
3. Josiah Thaw
4. Margaret Copley Thaw, Countess Margaret Carnegie de Périgny (1877–1942)
5. Alice Cornelia Thaw (1880–1955), who married George Seymour, 7th Marquess of Hertford
He died on August 17, 1889.
William Thaw endowed science fellowships at Harvard University and Princeton University and bestowed lavish gifts on art and education. He underwrote the building of the Allegheny Observatory for John Brashear, considered at the time one of the ten best in the world.
He is considered to have been one of the 100 wealthiest Americans, having left an enormous fortune. He was the father of Harry Kendall Thaw, whose 1906 murder of noted architect Stanford White resulted in a sensational trial and aftermath.
