 About 21.20% of families and 26.70% of the population were below the poverty line, including 35.50% of those under age 18 and 15.60% of those age 65 or over.Kleberg county is named after Robert Justus Kleberg Sr. (1803–1888), a Prussian settler, was born on September 10, 1803, in Herstelle, Westphalia.His father was a merchant.