James was born in Goochland County, Virginia at his father's plantation known as 'Belmont. He was the ninth child of Thomas and Caroline (Woodson) Bates. He started his advanced education at Yale but soon transferred to Princeton where he graduated in 1807. He read law and then went west. His older brother Frederick had been appointed the Secretary to the Missouri Territory in 1807. James and his younger brother Edward moved to St. Louis where he began the practice of law.

In 1819 the Arkansas Territory was created and Bates moved to its capital, Arkansas Post, to become one of the first lawyers in the new territory. That fall he was elected to be the non-voting delegate for the territory in the United States House of Representatives. He served two terms, from December 21, 1819 until March 3, 1823, and chose not to stand for re-election in 1822. While serving in Congress, he had moved to the small settlement called Poke Bayou. When the town plat was laid out in 1821, it was renamed Batesville in his honor.

But Bates was not a candidate for re-election in 1822, and when his Congressional term ended he returned to Batesville and resumed practicing law. He became a local judge in 1824, riding the fourth circuit through the western part of the territory. Then in 1828 John Quincy Adams appointed him to the superior court of the territory. He served until 1828 when President Jackson named judge Charles S. Bibb to the post.

While serving as a circuit judge he met and then married a wealthy widow, Elizabeth Moore. He moved to the Moore Farm near Van Buren in Crawford County. He later served as a probate court judge and a registrar in the land office.

In 1835 Bates was a delegate to the state convention the drew up the first constitution of the new State of Arkansas. He died in 1846, and was buried in the family plot on the Moore farm near Van Buren, Arkansas.