Yet political statement soon devolved into exhibitionist spectacle — partly by its own nature, and partly by human nature — proving that even in New York City, more than two decades after the New York State Court of Appeals ruled that toplessness is legal for women, taking advantage of that right still has the power to shock.

Shock and awe, of course, were part of the plan. A truck decorated with double-breasted balloons blasted, for reasons unknown, the Rolling Stones’ “Salt of the Earth.” One woman painted herself with Pokémon symbols; another dressed as an anime superhero; still others each wore a single enormous cloth breast. One brought an equally topless baby.

But they made clear that they were flaunting their chests for a cause.

“We have boyfriends that always take their shirts off, and we were like, ‘This isn’t fair,’ ” said Sarah Koon, 31, a musician who had come from Newark, Del., to New York with a few friends. She wore a bright pink wig, a black mask, black tape over her nipples and a chain for added symbolic heft.

She had thought about joining a topless march for several years, she said, but “it took me a while to build up the ovaries and actually do it.” (Her boyfriend, she added, is very supportive.)

But she was the only one in her group from Delaware who removed her top on Sunday. The rest were deterred by the gantlet of cameras that threatened to swallow the march.