In this excerpt from "Colonialism in the United States" by Henry C. Lodge, the word "indelibly" means "permanently" or "unforgettably." It suggests that something has made a lasting impression that cannot be erased or forgotten.
To understand the meaning of "indelibly" in this context, we can look at the surrounding words and phrases. In the excerpt, the author talks about how the Native American tribes have left their mark on the land and culture of the United States. He states, "Their traces and their work are indelibly stamped upon our country." This means that the impact of the Native Americans can be seen and felt everywhere in the United States, and it has left a permanent and unforgettable mark on the nation.
In simpler terms, "indelibly" means that something has made such a strong impression or impact that it cannot be easily forgotten or removed. It is like a mark that is permanently etched into a surface.