What are the biggest species of spider in the US?

Orb weavers comprise a huge family of Spiders, with 3500 species worldwide, 180 of which call North America home. These spiders vary greatly in color, shape and size, measuring between 2 - 30mm (1/16 -- 1 1/4") long. They have eight eyes arranged in two horizontal rows of four eyes each. The males are generally much smaller than the females and commonly lack the showy coloring of their fairer sex. They often spin their own smaller orb web near an outlying portion of the female's, and I've noticed most males give the females wide berth. Indeed, I rarely see male orb weavers, they are so reclusive.