Studying history gives us a certain amount of perspective when considering happenings today. Those who don't study history can tend to conclude that things used to be great and we're now living in the worst of times and things are continuing to go downhill. This can give them a sense of hopelessness and complacency with regard to the world today and a very pessimistic attitude about trying to do anything about the problems of today. The truth is that mankind has battled with (and sometimes lost to) great evil since the beginning of time. The perspective we gain from studying history, of course, also inspires us with the stories of people in other times who have acted heroically in the face of great obstacles.
We know that life experience tends to develop wisdom. We value the input of older relatives and friends who contribute wisdom and insight to our questions and problems. To a certain extent, studying history allows us to tap into some of that "life experience" for ourselves.
Probably the most famous quote about the study of history is "Those who do not study history are condemned to repeat it." We can learn from the errors of others and see certain things from a perspective other than our own. While certain errors of our own day loom very large to us, the dangers of taking other ideas to an extreme may be more subtle. For example, learning about the Albigensian Heresy (from sources such as St. Dominic and the Rosary by Catherine Beebe) holds a warning for our time about the dangers of taking conservative views too far.
We see how God raises up Saints and Heroes to combat every great evil faced by our Civilization. We see how even "ordinary" people (such as Oskar Schindler) can "rise to the occasion" when faced with great evil. We see examples and inspirations in historical figures for the difficult tasks that we need to face today.
As Catholics we are interested in seeing the role our Catholic faith played in history and recognizing the contributions of Catholics who have gone before us. We search for materials which include this point of view, but don't neglect other important aspects of History that aren't as directly related to our Catholic faith. A book which presents only the good side of Catholic history may not really be as Catholic as one which is more honest in its approach.
Also See: Why do we Read Historical Fiction?Related Links:
Teaching History and Science - the Who's and Why's by Dr. Anne Carroll
Light to the Nations: Reclaiming the Catholic Historical Imagination by Rollin A. Lasseter