In 1851, Lorenzo Lorraine Langstroth ( a Presbyterian minister) discovered that if you left a space (aprox 3/8") between the hive surfaces, the bees would work happily, building comb and tending their young without bridging this space.
This discovery allowed for the removable frame, which is the basis of commercial beekeeping World Wide.
The internal length of the Langstroth hive is 18 1/4 inches (463.6 mm), and internal width of 14 1/4 inches (362.0 mm). The exact size varies from country to country, and also depends upon machinery and manufacturer. (In practice, most beekeepers use only 9 frames in the honey super to improve frame manipulation, so exact size is never a problem).
While the full depth is the most economical size for commercial production, there are 5 comon sizes used in beekeeping. For supers, the sizes are :
Full Depth - A depth of 9 1/2 inches (241.3 mm)
Manley - 6 5/8 inches (168.3 mm)
WSP - 7 1/2 inches (190.5 mm)
Ideal - 5 3/4 inches (146.1 mm)
Half Depth - 4 7/8 inches (124 mm)
The frame depth is usually 5/16 - 3/8 inch (7.9 - 9.5 mm) less than the depth of the super.