William Thaw, Sr. (October 12, 1818 – August 17, 1889) was an American businessman who made his fortune in transportation and banking.

Net worth US$ 12 million at the time of his death (approximately 1/1040th of US GNP)

Spouse(s)

Eliza Burd Blair (m. 1841–63) ended in her death
Mary Sibbet Copley (m. 1867–89)ended in his death

Children

Benjamin Thaw, Sr. (1859–1933)
Harry Kendall Thaw (1871–1947)
Alice Cornelia Thaw (1880-1955)

Parent(s)John ThawRelatives

Russell William Thaw, grandson

Biography

He was born in Pittsburgh, Pennsylvania on October 12, 1818 to John Thaw and his wife Elizabeth Thomas. 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:

• Eliza Thaw, wife of George B. Edwards
• William Thaw, Jr.
• Mary Thaw, wife of William R. Thompson
• Benjamin Thaw, Sr.
• Alexander Blair Thaw (1860–1937)

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:

• Harry Kendall Thaw (1871–1947), who would later murder Stanford White In his will, he left $10,000, less than 1% of his fortune, to wife Evelyn Nesbit.
• Edward Thaw
• Josiah Thaw
• Margaret Copley Thaw, Countess Margaret Carnegie de Périgny (1877–1942)
• Alice Cornelia Thaw (1880–1955), who married George Seymour, 7th Marquess of Hertford

He died on August 17, 1889.

Philanthropy

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.

Legacy

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.