North American railroads until the mid- to late-20th century used rails 39 feet (11.9 m) long so they could be carried in gondola cars (open wagons), often 40 feet (12.2 m) long; as gondola sizes increased, so did rail lengths.

The traditional length of railroad rails in North America was established as 39 feet primarily for logistical reasons involving transportation. Historically, the standard "gondola" freight cars used to transport rails from the steel mills to the tracks were 40 feet long. By manufacturing the rails to be 39 feet, the mills ensured that they would fit comfortably inside these cars with a few inches of clearance at each end, preventing damage to the car ends and allowing for easier lifting and unloading by cranes. While the industry has since moved toward Continuous Welded Rail (CWR), where rails are welded into sections thousands of feet long, the 39-foot "stick rail" remains a legacy standard. Some historical accounts also suggest that 39 feet was a multiple of the 3-foot "yard" unit and conveniently fit within the early rolling mill capabilities. Today, though longer "double-length" rails of 78 feet are also common, the 39-foot measurement remains a fundamental unit of railway engineering history that dictated everything from mill design to rail car dimensions for over a century.