Alger entered Harvard College in 1848. He became a professional writer the following year when he sold two essays and a poem to a Boston magazine. He was elected to Phi Beta Kappa, a fraternity for outstanding scholars. He graduated in 1852, ranking eighth in a class of eighty-eight. He went to Harvard Divinity School in 1853. He quit the same year to take a job as an assistant editor with a Boston magazine. He hated editing, and quit in 1854.