Complex sentence: In October of that year, she began her last supply run; and, after delivering medical stores to ships at Helena and on the White, Red, and Yazoo Rivers, she transferred patients to Hospital Pinckney at Memphis, Tennessee, and headed north.
Split into simpler sentences: In October of that year, she began her last supply run. After delivering medical stores to ships at Helena and on the White, Red, and Yazoo Rivers, she transferred patients to Hospital Pinckney at Memphis, Tennessee and headed north.