The 1854 Gazetteer of the United States by Thomas Baldwin shows:

PUTNAM, a county in the N. central part of Illinois, has an area of 200 square miles. It is intersected by the Illinois river, navigable by steamboats. The surface is nearly level or undulating; the soil is highly productive and easily cultivated. The county contains extensive prairies, and is liberally supplied with timber. Indian corn, wheat, grass, and pork are the staples. In 1850 it produced 279,260 bushels of corn; 88,771 of wheat; 48,494 pounds of butter, and 3732 tons of hay. It contained 8 churches, 880 pupils attending public schools, and 110 attending other schools. Stone coal is found in this county. It is intersected by the Illinois Central railroad. Organized in 1831. Capital, Hennepin. Population, 3924.