Ok,
Unless someone is a professional climatologist or at least a meteorologist I think we are going to have to disagree. That being said:
1. All data regarding climate taken before the 1970s (or at least the 1960s) is going to be far less reliable than data from later years. The reasons are simple. Prior to climate observation satellites being launched, temperature records essentially were based on collecting local observations. These observations tended to be biased towards areas with large populations (i.e. cities) and thus large areas could have poor coverage and thus not have their temperatures properly recorded.
2. The United States, while large, is not the same as the entire Globe. The key to global warming is world wide trends, not local or even continental trends. Even during ice ages, there were probably parts of the equatorial belt that experienced years of extreme heat.
3. Consensus may not be science, but it is the best tool for the public to gauge the scientific data. Most hypothesis and theories go through a stage when few in the scientific community believe them. Over time, experiments and observations will start to confirm or deny the the hypothesis or theory. As the theories are confirmed, more and more scientists will jump on the band wagon. Now every conclusion in science is always tentative; always subject to change based on new observations. That being said, most scientists, ultimately recognize when they are beating a dead horse and will ultimately accept the theory that has the most evidence for it. At the same time however, there will almost always be scientists who resist the consensus for a long time; for example, Fred Hoyle, to his dieing day, resisted the Big Bang/Inflation model for the creation of the Universe it didn't make him right, just stubborn (Though he may be right.. check back in on cosmology in 50 years
).
Just a general thought; most scientists I have had the pleasure of meeting, regardless of their politics, hate being wrong. What they hate more though is cooking the books. They would prefer show they are wrong than ever fake their data or their conclusions to agree with their politics.
--
Bill