This does not count civil disobedience, e.g. blocking traffic as form of protest. I am referring to someone being arrested in contravention of the First Amendment as understood in law for writing or speaking something that the powers that be don’t like.
I wouldn’t be surprised if this happens frequently, a common form being someone speaks very negatively to a police officer, he is arrested, released the next day and charges never brought by a prosecutor. But I’m probably just too cynical.
Part of the answer would get into the gray area of disclosing items of military or national security, at which point you have to judge the merits of the material disclosed against its value as a secret.
I believe there were some flat-out dissent arrests, perhaps even trials, in the late 1960s. The Chicago 7 were effectively tried for dissent, but on alternate charges, for example.
Arrests probably happen all the time, but as to how many are actually even brought to trial, that’s a vanishingly small number, and the number of actual convictions is probably close to, or actually zero.
There were a number of post-Schenck arrests (and subsequently convictions) under the Sedition Act of 1918. Really, we need a better definition of dissent. Demanding the immediate violent overthrow of the government is dissent but I don’t think that’s necessarily within the scope of what we’re looking for.