Final answer:
The ineffectiveness of quinine during the Mexican-American War sparked the enactment of the Drug Importation Act of 1848, addressing the purity and quality of imported drugs.
Step-by-step explanation:
The crisis during the Mexican-American War where quinine was ineffective against yellow fever because it was thought to be adulterated led to the Drug Importation Act of 1848. This legislation was enacted to ensure the purity and quality of drugs being imported into the United States, like quinine, which was a widely used antimalarial drug derived from the bark of the cinchona tree.
The Drug Importation Act was one of the first federal laws to regulate drugs and addressed concerns about drug adulteration, which were common at the time. This early legislation laid the groundwork for future drug regulation.