Final answer:
The text suggests Friedrich von Steuben was gay because he never married, had no children, and left his estate to three young men with whom he shared a close relationship, which historians view as indirect evidence considering the era's stance on homosexuality.
Step-by-step explanation:
The text provides support for historians' belief that Friedrich von Steuben was gay through indirect evidence. Firstly, von Steuben never married nor had children, which was uncommon for men of his era, particularly those of high social standing. Secondly, von Steuben's close relationships with men are highlighted by the fact that he left his estate to two young men he had adopted and another who considered himself part of von Steuben's family. While not definitive proof, given the era's laws against homosexuality, historians interpret these close male bonds and von Steuben's lack of a traditional family as potential evidence of his homosexuality.