If I understand the question correctly, you are asking what makes someone a man in the socially accepted example. Considering that gender lines have slowly been disappearing since the 1960s, you'd think it would be more difficult to tell what would make someone a man. It used to be providing for your family and being an upright citizen (as in not having a criminal record or cheating/beating on your wife, not merely just someone who can stand up), but with single parents and artificial insemination these days, there's not much call for the old standards.
What makes it more difficult is location in some circumstances. Some people won't view you as a man unless you've been jail, killed someone, or performed oral sex on a dead woman knowing she had the clap when she died. In a religious sense, there is a lot of examples that I probably don't need to go in to, so I won't. In America, the lines have become rather blurred in the last fifty years, and I'm surprised I don't see more creative answers than "if he's got a dick, he's a man". What a lameass copout answer, people.
I still say it is taking care of your family, not intentionally trying to screw people over, and keeping your ass out of jail/family court. What I absolutely HATE is when a woman tells you to "man up". Going by everyones' answers, since women (at least a significant number of them that aren't transgender) don't have a dick, therefore have no other gauge as to tell a man how to be a man. And it is always a situation that doesn't require a dick to solve, either. It is easier to say how to emasculate someone than it is to say what determines their masculinity. Strange how life works out like that.