So called "Critical thinking" is a collection of skills and history only maps to some of them. The skills that I believe history fosters at the margin, i.e. independently of any other subject, are the following:
- For intellectual history: understanding not only that an idea might have "prior art" that can be worth learning from (to evade errors, to find interpretations you didn't consider), but also understanding the lineage of how the idea was constructed and passed on, calibrates you as to both the originality and the level of independent confirmation you can give to it. If many people come to the same conclusion from different angles, great! But in all likelihood the idea has a few core progenitors that everyone is drawing from. If this is the case, then you know to discount the fact that "everyone is doing it" away from your evaluation of the idea, and focus on the original source itself and maybe a few key proponents.
- For societal history: too often I think we underestimate what is possible for human beings to do or achieve, both the height of our accomplishments and the depth of our horrors. Societal history also lets us understand what we have precedents for, which is critical in law. I don't believe it is much use to use history for "trend-seeking", not without some conceptual augmentation (see below cf. economics), but it can definitely help to lower your surprise.
- For historiography: taking the notion "primary", "secondary", "tertiary" etc hierarchy of sources to heart, and the level of prior validity you can expect from each one, lets you understand how difficult it is to separate bias from an account of an experience, as well as encourage coming to your own interpretations by seeking the original data.
However, despite these advantages, I don't think that history is the best field for critical thinking. I believe that trophy should go to economics. Why? The reason being that economics is a field of endeavor that is a source of non-narrative (read: not bullshit prone) explanations of historical phenomena, but also extends these models to the present day and even could allow predictions of the future. Other than citing precedent and giving you evidence to feed into your thinking, history alone doesn't directly let you do this in a fashion I would consider acceptable.