I hate to break it to you, but President Reagan, Vice President Cheney, Sarah Palin and Steve Bannon were/are not libertarians, small L or otherwise. Perhaps you mean classical liberal, which is what most modern conservatives actually are? Leftists usurped the "liberal" term even though they are the most illiberal of people.
Libertarianism is basically social anarchy and hedonism combined with low taxes in a strange utopian mix that pretends it’s somehow “conservative”.
I hate to break it to you, but "classical liberals" had a lot more than in common with modern day libertarians than modern day conservatives. Using the term "liberal" a century ago was always in the context of someone who was ECONOMICALLY conservative and believed in a free-market system and Laissez-faire financial sysems. It NEVER meant a belief in social conservativism, traditional values, or a strong national defense.
People who were "liberal" centuries ago on religious beliefs and morality would still be "liberal" on those topics today!