20 Dollars James K. Polk

Liberia's late-1990s and early-2000s commemorative program was among the most prolific — and commercially cynical — in modern numismatic history, producing hundreds of licensed issues aimed squarely at the American collector market rather than domestic circulation. This Polk piece is a product of that pipeline, struck almost certainly by a European contract mint and never intended to see a single Liberian hand.

Polk himself remains historically underrated: he annexed Texas, prosecuted the Mexican-American War to its conclusion, acquired the Oregon Territory, and declined a second term — all within four years.