It depends, at least in part, on what you mean by "large scale civilization". I can speak to prehistoric monumental architecture and complex society in North America north of Mexico. Certainly, prehistoric Mesoamericans had a rich legacy of monumental stone architecture as evidenced by Mayan and Aztec ruins. They also had urban centers, political organization, task specialization, intensive agriculture and other hallmarks of complex society. And there was a tradition of monumental architecture and complex society in South America, as well. But I have no actual expertise with these areas so I will limit my comments to north of Mexico.

Native North Americans had monumental architecture in complex hunter-gatherer civilizations as early as 3,500 years ago (see Poverty Point site ). Note that the Poverty Point Site has a road constructed right through the middle of it. Complex societies emerge in the Northwest Coast area beginning about 3,500 years ago also. The Hopewell period evidenced effigy and geometric mound building from the Great lakes to the Southeastern woodlands from 2,100 years ago to 1,500 years ago. There exists a littany of Hopewell mound sites that have had houses, golf courses and, in fact, towns built on them. The Mississippian Period (1,200 years ago to contact) had large temple mounds and intensive agriculture in cities of tens of thousands. /u/Reedstilt has a great post about these Mississippian period sites here. In fact there is a section on monumental architecture in this site's wiki.

In addition, there were complex societies in the American Southwest. Puebloan cultures built large cities in adobe and stone over an immense area in the desert Southwest. /u/RioAbajo has a great discussion of Pueblo households here. There were also complex cultures in the Pacific Northwest among specialized fisher-gatherers. The Northwest Coast Culture Area had large coastal or riverine towns, inhabited by a socially stratified society that boasted task specialization, clans and moieties, splendid wooden architecture and a host of complex community rituals.

So the answer to the first part of your post: "that there were large scale civilizations" is accurate as evidenced by Mesoamerican cultures, Puebloan groups and Mississippian period peoples of the eastern woodlands. Complex society was also observed among Northwest Coast people and others but they employed wood architecture which is not so great for preservation of ruins.

There were significant remains (ruins) of these settlements at the time of contact and many persist in conservation status today. The process of colonization certainly displaced the occupants of many of these sites. Subsequently, many, many residential sites of native North Americans were destroyed by development, treasure hunting/artifact collection, and by vandalism. /u/sunagainstgold provides an apt discussion of the destruction of mound sites in St. Louis near the Mississippian urban center of Cahokia elsewhere in these comments. But there are horror stories of the destruction of important sites throughout the continent.

To the second part of your question: "that there were actually ruins from their civilization all over the US before we developed their land.", the answer is yes, there were. The pattern of European expansion and the demise of native culture (including material culture) are inextricably interwoven in North American history and prehistory. The demise of native cultures was extraordinary in scale and brutal in detail. /u/anthropology_nerd has a great post on the contact impacts in the Southeast. And I don't think it is accidental that many of the early archaeologists that excavated native sites were looking for an earlier "up-to-now undiscovered people" because the remnant native people they could see then, the people who had been subjected to war, plague, displacement and enslavement, were not perceived as capable of creating the artifacts and features that they observed. This is absolutely true in the Northwest and I suspect it is true throughout the continent.

Certainly, I don't think that the general public has an appreciation of the complexity and richness of native NW culture. That is in a large part our failure as historians and prehistorians. I suspect that there is not much knowledge of Native American culture in the greater U.S., and that is, in part, because evidence of their settlements and architecture has been obscured by recent development. A not insignificant and uncomfortable factor is that the native people themselves were obscured by the development of white culture in North America. So I would say that the information you read on twitter is pretty much on the spot.

Notes: Tony Platt's Grave Matters: Excavating California’s Buried Past (2011) has a great discussion of the state of Native Americans and archeologist's perceptions in California in the early 20th century.

Edit: Numerous typos and grammar revisited several times.