Unidentified Photographs of non-Acton Scenes

Among the photographs held by the Society are some of scenes that are clearly not Acton.  They may have been taken by or sent to Acton people, but we need help in identifying the times and places and, ideally, any Acton people that may have been included.  Can you help us?

Is the horse pulling a street sweeper? If not, what is it pulling? Where and when was the photo taken?

A sign on the building says "Lexington St."  Is this a parade in East Boston?  Did the float (manned by minutemen) have Acton connections?  It seems to have come with a collection of pictures that included names of Wetherbee, Flagg, Robbins and Rouillard, probably East Acton.