Final answer:
Children under age 18 have the highest percentage of poverty in the U.S. population, despite the historical decline in poverty among the elderly since the 1960s.
Step-by-step explanation:
The age category of the U.S. population with the highest percentage of people in poverty is children under age 18. This conclusion is based on various tables and figures depicting U.S. poverty rates over time for various age groups. While seniors over the age of sixty-five experienced a decline in poverty from 30 percent in 1967 to 9.7 percent in 2008, the poverty rate for children has consistently been higher. The impact of the 2008 recession also highlighted that some elderly individuals faced financial challenges that could lead to late-age destitution, but overall, children still represent the group with the highest poverty rate.