Despite the term's largely pejorative connotation, propaganda is not by definition false or misleading or harmful. Propaganda is anything of a verbal or pictorial nature that is propagated to influence behavior. Propaganda can consist of truths or falsehoods, good advice or bad, exhortation to good behavior or subornation of bad. Anti-smoking and anti-drug messaging are propaganda but the messages are salutary. Leftist propaganda is destructive while conservative propaganda inspires ameliorative action.
Here is a very good collection of visual propaganda from yesteryear.