John Lowell Gardner Jr. was one of seven children of John Gardner and Eliza Peabody. He married Isabella Stewart on 10 April 1860. They had one child, John Lowell Gardner (1863-1865) who died in infancy.
'Jack' Gardner was a wealthy Boston financier. Through his sister Julia he met Isabella Stewart in Paris and they were married on 10 April 1860.
They met Whistler in Paris and bought several works from him; it is not clear whether Jack Gardner had much input in the choice of works by Whistler.
She began seriously collecting art and her collection grew so large that when their house in Boston was completely full, they bought the house next door. The Gardners had already begun planning the creation of a museum in 1898, the year of John Lowell Gardner's death.
http://members.aol.com/Gardner476/Salem9.html (accessed 2004.6.9)