Many Native American tribes built large houses. The longest Native American houses were the longhouses built by the Iroquois and Algonquian
tribes of the eastern USA. These houses could be 200 feet long, 20 feet wide, and 20 feet high. Tribes on the Northwest Coast (from Washington
state up to southern Alaska) used to build large plank houses out of cedar trees. They weren't as long as longhouses but they were wider, so their
overall size was similar.
Also, individual Pueblo adobe houses were not very large, but they were built next to and on top of each other in huge complexes like apartment
buildings. If you consider a complex of Pueblo adobe houses to be a single structure, then those are even larger than longhouses or cedar plank houses.
But in Mexico, there were some structures built before Columbus landed that were even bigger than Pueblo house complexes and those are the
pyramids of the Aztecs and Mayas. In fact, according to the Guiness Book of World Records, the Great Pyramid of Cholula in Mexico is
the largest monument ever constructed anywhere in the world!