Anthony joined the Post Office in 1834, at age 19, working at first as a clerk. In 1841, he became postal surveyor in Ireland. After his marriage to Rose Heseltine in 1844, Trollope set up a house at Clonmel, where he began to write. His first book, The MacDermots of Ballycloran, was published in 1847. His first novel in the Barsetshire series, The Warden, appeared in 1855, and was followed by other successful novels: Barchester Towers (1857), Framley Parsonage (1861), and The Last Chronicle of Barset (1867).

Trollope worked for the Post Office for 33 years. On Post Office business he travelled in Egypt, the West Indies, and the United States, and by the end of his professional career Trollope had became a successful civil servant. Among his achievements is the introduction of the red British mail boxes for letters, known as "pillar-boxes." Before the introduction of mailboxes one had to go to the Post Office to mail a letter.

In 1859, Trollope moved back to London and resigned from the Post Office in 1867. He ran for Parliament, in 1868, but was unsuccessful.

Between the years 1867 and 1870 he edited the St. Paul's Magazine. In 1869, Trollope began a series of political novels, known as the Palliser series, including Phineas Finn (1869), The Eustace Diamonds (1873), Phineas Redux (1876), The Prime Minister (1876), and The Duke's Children (1880). Among his other later novels were The Way We Live Now (1875) and Mr. Scarborough's Family, which was published posthumously in 1883. In all, Trollope published some 40 novels, short stories, travel books, and essays.

• The Warden (1855)
• Barchester Towers (1857)