Using a version of the federal government’s Supplemental Poverty Measure (SPM) — a more comprehensive metric than the official poverty measure — we calculate that the poverty rate has fallen by nearly half since 1967, largely due to the growing effectiveness of economic security programs such as Social Security, food assistance, and tax credits for working families. Poverty fell from 26.0 percent in 1967 to 14.4 percent in 2017 by this measure. Most of the improvement came from economic security programs. Earnings and other non-government sources of income did not improve sufficiently over this period to reduce poverty substantially.