Knopf, Alfred A. (1892-1984). President of New York publisher Alfred A. Knopf, Inc. Knopf received his BA from Columbia University in New York City in 1912 and founded Alfred Knopf, Inc., in 1915 with his future wife Blanche Wolf. They married in 1916, and their son Alfred “Pat” Knopf was born in 1918. Cather chose him as her publisher beginning with Youth and the Bright Medusa (1920) and One of Ours (1922), partly because she was dissatisfied with the promotion of her books by Houghton Mifflin but also because she recognized the high quality of Knopf's books, as well as what she regarded as his intelligent advertising. Knopf was noted for publishing the work of leading European and South American writers in translation, as well as original works. Knopf and Cather’s extensive correspondence testifies to their mutual professional respect and to what also became an important personal friendship.

Hambourg, Isabelle McClung (1877-1938). Cather’s longtime friend. Cather met Isabelle McClung, the daughter of a socially prominent, Pittsburgh (PA) family, in 1899 in the dressing room of actress Lizzie Hudson Collier. McClung seems to have been the first woman to reciprocate Cather’s romantic affections. In 1901, McClung invited Cather to live in her family’s large home in the Squirrel Hill neighborhood of Pittsburgh. She and Cather traveled together to Europe in 1902, and McClung accompanied Cather on a visit home to Nebraska in 1905. After Cather moved to New York City in 1906, she frequently visited McClung in Pittsburgh, finding the familiar house a congenial place to write, and McClung visited New York City, staying with Cather and Edith Lewis. Cather and McClung also rented a vacation cabin in Cherry Valley, NY, in 1911, and traveled together to Virginia in 1913. In late 1915, shortly after the death of her father, Judge Samuel McClung, Isabelle announced her intention to marry violinist Jan Hambourg. Cather reacted negatively to the marriage (which took place in 1916) but eventually reconciled herself to it, enjoying long visits with the Hambourgs in Toronto, Ontario, in 1921 and France in 1923 and 1935. Cather and Edith Lewis also spent time with the Hambourgs in Paris is 1930 and 1935. The latter trip occurred after Isabelle sought treatment in the U.S. for the kidney disease that killed her several years later in Italy. Her death came only four months after Cather’s brother Douglass died, leaving her feeling bereft. “No other living person cared as much about my work, through thirty-eight years,” she wrote her brother Roscoe (#2137). After Isabelle’s death, Jan sent to Cather the six hundred letters from Cather to Isabelle in his possession, and Cather destroyed them, although a few letters from Isabelle and Cather postcards to Isabelle are extant.

Hambourg, Jan (1882-1947). Russian-born violinist; Isabelle McClung’s husband. Hambourg moved with his family to Toronto, Ontario, in 1910, where he was the head of the violin department at the Hambourg Conservatory and performed as part of the Hambourg Trio. He married Isabelle McClung in April 1916. Cather reacted negatively to both Hambourg and the marriage, but she gradually came to accept him. Beginning in the 1920s, Hambourg left the family conservatory and focused on solo violin performance in Europe. Cather enjoying long visits with Isabelle and Jan in Toronto in 1921 and France in 1923 and 1935. She dedicated The Professor’s House (1925) to him (“For Jan, because he likes narrative”) and asked him to make musical corrections to Lucy Gayheart (1935). When Isabelle died, Jan sent to Cather the three hundred letters from Cather to Isabelle in his possession, and Cather destroyed them.