An Ax to Grind: A Practical Ax Manual
Brief History of the Ax, continued

Ax Types, Patterns, and Uses
During the 19th century, America's agrarian society was not as mobile as our society is today. People lived their lives in relatively small geographic areas. This is one explanation of the hundreds of different ax-head patterns that developed over the last 150 years.
The individual skills of local blacksmiths and their view of what an ax needed were important factors in the development of ax-head patterns. Ax patterns became a matter of regional preference.