Does chess help develop moral virtues or correct practical attitudes? Benjamin Franklin wrote a famous essay on the virtues of chess, claiming that it teaches foresight, circumspection, caution among others.

Kasparov Chess Foundation's mission is to bring the many educational benefits of chess to children worldwide by providing a complete chess curriculum and enrichment programs. The Foundation promotes the study of chess as a cognitive learning tool in curricular classes and after-school programs for elementary, middle and high schools, both in the public and private school sectors.

This mission statement presupposes that there actually are educational benefits of chess.

Is there any argument to support the claim that chess can help develop moral virtues or practical skills? Or is it perhaps just the wishful thinking of chess playing philosophers and philanthropists?
Chess definitely helps with intellectual development and education. Math is the most obvious area where chess definitely helps. There is a lot of research to back this up. If you think about it, chess develops general mental abilities including: strategic competency; the ability to analyze variations; spatial relationships and interdependencies; self-confidence in the face of complex problems. All of those abilities are generally useful in solving all kinds of problems in school and life. 

Here are links to some web resources where you can read more about the well-documented benefits of chess in education. 

http://education.jhu.edu/PD/newhorizons/strategies/topics/thinking-skills/chess/

http://www.psmcd.net/otherfiles/BenefitsOfChessInEdScreen2.pdf

These are just two examples. There are a lot more articles out there on the Internet, and they mostly arrive at the same basic conclusion. 

Moral virtues are another story.

Chess doesn't directly help with moral values. Bobby Fischer was a great example of this. He was a brilliant chess player, but widely regarded as the worst kind of person. He had very clever and elaborate arguments to support his negative and self-destructive points of view. There are many examples of top level chess players who are wonderful people, but also quite a few examples of immoral behavior among grandmasters.