In 1861, he was appointed minister to Turkey, but even though it had been confirmed by the United States Senate, he declined. According to biographer Glyndon Van Deusen, "Webb, an inveterate beggar for office, wanted a diplomatic appointment that would be lucrative." Shortly afterward, Webb was appointed minister to Brazil and served in that position for eight years, resigning when he was accused of extorting a large sum of money from the Brazilian government. At Paris in 1864, Webb claimed he was instrumental to negotiating a secret treaty with Emperor Napoleon III for the removal of French troops from Mexico. Abraham Lincoln's biographer, Carl Sandburg, wrote that Webb "believed that Lincoln should have appointed him major general, rating himself a grand strategist, having fought white men in duels and red men in frontier war." In 1869, he resigned the mission to Brazil, and returned to live in New York. On July 1, 1823, Webb was married to Helen Lispenard Stewart (1805–1848). Helen was the daughter of Irish born merchant Alexander L. Stewart and Sarah Amelia (née Lispenard) Stewart (the granddaughter of Leonard Lispenard). Before her death in 1848, they were the parents of:   On November 9, 1849, he married Laura Virginia Cram (1826–1890), the daughter of Jacob and Lydia (née Tucker) Cram. Webb lived for a time at the present-day 7 Pokahoe Drive in Sleepy Hollow, New York, a house that was later owned by John C. Frémont (the house is currently a private residence). Together, they were the parents of:   Webb died in New York City on June 7, 1884, surrounded by his children. General Webb was buried at Woodlawn Cemetery, The Bronx. Webb published the following: