The Irish name Jennings is the anglicized for of Mac Sheoinin. It was adopted as a surname by a branch of the Burkes of Connacht, who were descended from Seoinin (Little John) Burke. Jennings is also independently, a common English name, which, no doubt has also made its way to Ireland over the centuries.
There is early mention of John Jennings (alias Burke), who was Bishop of Tuam from 1441-1450. Also Charles Jennings (1744-1799), Irish soldier, who fought in the French Revoilution...
The surname Jennings was first found in Connacht (Irish: Connachta, (land of the) descendants of Conn), where, at the time of the "Composition of Connacht," in 1585, they held extensive lands in the baronies of Dunmore, County Galway and Kilmaine, County Mayo.
Jennings Settlers in United States in the 17th Century:
Miss Mary Jennings, who left England and arrived in Maryland in 1634 aboard the ship "Ark and Dove"
Nicholas Jennings, aged 22, who landed in New England in 1634 aboard the ship "Francis"
Jane Jennings, aged 25, who arrived in Virginia aboard the ship "David" in 1635
Jon Jennings, who arrived in Virginia in 1635
Rev. Henry Jennings, aged 24, who arrived in Bermuda, (Somers Islands) in 1635 aboard the ship "Truelove"
Jennings Settlers in United States in the 18th Century:
William Jennings, who landed in Leeward Islands in 1703-1704
Jennings Settlers in United States in the 19th Century:
George Jennings, who landed in New York in 1826
Charles Jennings, who arrived in New York in 1835
Joseph Jennings, who landed in New York in 1835
Edward Jennings, who landed in New York in 1838
Mr. J. Jennings, (b. 1836), aged 30, Cornish settler departing from Falmouth aboard the ship "Cornwall"
arriving in the United States on 3 June 1841.