I responded to a reader's query in 2007 about the peculiar Baltimore terms A-rab and Arabber for a street peddler or huckster, explaining that the term probably originated from the nineteenth-century term street arab, a homeless child living by his wits. You may want to look at the original post, because the ever-industrious Grant Barrett did some research and appended a highly informative comment.

Now I have a message from Dee Lightner about the term, which she has given me leave to publish:

"When I was growing up (in the 40s and 50s) the street vendors that came around to the various neighborhoods were called what they bought or sold (that is, the junk man who bought 'junk', and he was also called the 'rag/bone' man, because what he would holler sounded like he was saying rag-bone, and the ice man and the vegetable or fruit man etc.)
"I lived out of the area for many years, but when I moved back in the early 90s, all of a sudden everyone, when speaking about the 'old days' in Baltimore, was calling ALL the street vendors 'Arabers'.
"I have talked to quite a few older folks who also grew up in Baltimore and they all say the same thing, that the street vendors were NOT called Arabers in the old days.
"My thinking is that as neighborhoods became 'gentrified' the term for the 'junk man' got gentrified, too.  I mean, what 'yuppie' would want to speak of the history of their upscale neighborhood, and mention that the JUNK man used to be a fixture!
"Can you help determine when the term Arabers began to be in common use?  Did it originate when someone wrote about Baltimore history and coined the term, or borrowed it to be a blanket term for all the street vendors?"
To clarify: In The American Language H.L. Mencken dates the term, which he spells Araber, to his youth in the 1880s and 1890s. Grant Barrett points out that the specific application to vendor dates from 1935 in the Dictionary of American Regional English. In my time, the past quarter-century, arabber specifically meant African-American street vendors who sold produce from carts drawn by ponies. 
Can anyone help with Ms. Lightner's query? Did arabber once include the junk man, the rag-and-bone man and any other street peddler, or was it restricted to a specific group of produce sellers? Testimony from memory would be welcome. Evidence from printed sources would be invaluable.