Not everyone's a history buff. Not everyone's even heard of the Dreyfuss affair of 1894-1906.
But of those who have heard of the Dreyfuss affair, most can probably identify at least one of two, and perhaps both, figures involved.
Figure One: Albert Dreyfuss, the French soldier accused of spying for Germany; and
Figure Two: Emile Zola, a French writer who was prosecuted for "defamation of a public authority" over his open letter on the matter (J'Accuse ... !)
Quiz: Name any of the Presidents of the Council of Ministers of France (the rough equivalent, at the time, of Prime Ministers in parliamentary systems or presidents in the US system) during the period.
Offhand, I was able to name a grand total of one of them, out of several. But that one came to the position at the very end of the affair, and was previously Zola's publisher and co-defendant, Georges Clemenceau.
The Point: 120 years from now, it may be that not a whole lot of people will know much about the Manning affair. But of those who do, I bet more people will be able to name Chelsea Manning and Julian Assange, the equivalents of Dreyfuss and Zola, than will be able to name any of the US presidents in office at the times of their persecutions.