http://www.monticello.org/site/research-and-collections/jeffersons-excavation-indian-burial-mound) No one is known to have scientifically performed an excavation before this and his methods were comparable to that of archaeologists a century later.
Thomas Jefferson was not the first or the last one to excavate a burial mound, but the reason that he is credited as an innovator and pioneer is that he recorded what he found. If we do not record and share information, others cannot benefit from our work. If one person shares information, others do not have to do the same work for the same information: everyone benefits. Christopher Columbus was not the first European to the Americas, but he was the European to spread the word (a good example of what I'm talking about even though it not from the eighteenth century). When information is shared, other people are able to contribute the information that they have and the entire group is made better for it.
(Hooray! I found out how to put pictures in my posts!)