Members of the Choctaw Nation collected $170 in 1847 and sent it to Dublin to help feed the Irish during a potato famine. The money would be worth about $4,400 today.
Prime Minister Leo Varadkar met with tribal members on Monday in the southern Oklahoma city of Durant as part of a weeklong trip to the U.S. He said the gift is a sacred memory and bond.
The gathering included Oklahoma Gov. Mary Fallin, who said she was supporting the Choctaw Nation and Oklahomans.
Choctaw Chief Gary Batton visited Ireland last year to attend the unveiling of a sculpture called Kindred Spirits that commemorates the relationship between the tribe and Ireland.