US 50 is one of the longest highways in the U.S. How long is it? Well, there's actually some debate on that (this page has more details about why that is).
Both the Maryland and California state departments of transportation have placed reciprocal mileage signs at the terminus points, each claiming the total distance is 3073 miles. This photo was taken in Ocean City MD, looking along the east beginning of US 50...
In 1967 the US 270 designation was at its maximum extent, from Pine Bluff AR to Syracuse KS. That year the Kansas DOT petitioned AASHO* to extend the US 270 designation even further: