Why was the Northern army better supplied than the Southern one?

The Northern army was better supplied than the Southern army primarily due to the North's industrial capacity and extensive railroad network, which facilitated the production and transportation of weapons, ammunition, food, and other supplies. The Union's larger population also provided a greater labor force to support its military needs. Additionally, the North's control of key ports allowed for better logistics and access to resources, while the South faced blockades and shortages that hindered their supply lines.