This conformal projection was constructed specifically for mapping North and South America. It is composed of two oblique adaptations of the Lambert Conformal Conic projection. The juncture of the two conic projections consists of a great circle arc cutting through Central America from southwest to northeast. There is a slight mathematical discontinuity along this arc, which is resolved by an adjustment that leaves a small intermediate area slightly non-conformal. The earth is treated as a sphere by this projection, due to the relatively small scale of the map.
The "Bipolar Oblique Conformal Conic" Projection has no parameters, as the poles and parallels used by the conic projections are set to specific values.