It's not unusual that Trump is picking government outsiders to staff his Cabinet, given who Trump is. It is, however, unusual for a secretary of state to have no experience in public service at the federal or state executive levels. In fact, by our analysis, it's unprecedented.
We walked back through the history of the country's secretaries of state (those confirmed, not just acting). At no point has a previous secretary had no experience in government as above.
There are a number who had little or unusual service, certainly, particularly at the time that they assumed the position. Thomas Jefferson, for example, hadn't served in the United States Congress, having been only (“only”) governor of Virginia and minister to France. He later went on to other government positions. John Marshall served one lousy year in Congress before being tapped to run the State Department. (Again, there are obviously some asterisks that apply.)
Often, the experience held by secretaries of state was in Congress or stints in the executive branch. Those stints, though, usually followed years of work in the broader orbit of international diplomacy.
Some had a surfeit of experience. Lewis Cass ran for president, sat in the House and the Senate, served as governor to the Michigan territory (which we didn't count for our purposes), served as secretary of war (later defense) and was ambassador to France — all before joining State. I'm very confident that Edward Livingston will be the only secretary of state who also at one point served as mayor of New York and a member of the House from Louisiana. (Maybe Bill de Blasio has big ambitions, who knows.)
Tillerson's international experience, as articulated by the official statement from the Trump transition team, is that he “knows how to manage a global organization and successfully navigate the complex architecture of world affairs and diverse foreign leaders.” That's certainly the case. It's just not the experience that we've come to expect from past people nominated for the same position.
Which, of course, is just fine with Trump.