During the 19th century, the growth of the American population paralleled rising demand for transportation of goods, people, and commercial products across the country, and railroads transformed that movement. Frontier-era limits on access to fruits, vegetables, and dairy products gave way as railroad tracks reshaped markets and distribution. Cowboys on the open range, wagons on the Santa Fe and Oregon trails, and steamboats on the Missouri could not match the iron horse’s ability to serve a booming population. As late as 1852, steamboats still dominated transportation, but by 1890 railroads crisscrossing the nation had become the dominant means of moving goods. Rail shipment brought greater profit than river boats by cutting transit time and reducing cargo loss, while lower transportation costs reduced retail prices. Expanding markets encouraged farmers to raise more cash crops such as corn, wheat, and sorghum, and some also supplemented their income by harvesting timber for railroad ties. Producers of perishable goods benefited especially. Before railroads, some cities were so crowded that importing fresh milk was nearly impossible, leading to unsanitary urban dairies where cows were fed distillery and brewery slop along with kitchen garbage. Health regulations and refrigerated train cars increased milk delivery to urban areas and ended those dairies. From 1842 to 1843, 750,000 gallons of milk were delivered to New York City. Wisconsin’s rail link to Chicago helped make the state a prominent dairy provider, and the spread of railroads into the South and West let cities import steady supplies of fresh fruits and vegetables, making highly perishable produce such as strawberries readily available to urban residents.