Richard,

If NYC pushcart license records still exist that would be an interesting new genealogy resource.

Interesting article from The Tenement Museum:
https://www.tenement.org/blog/when-life-gives-you-lemons-sell-them-on-the-lower-east-side/
"In 1899 the price of a municipal pushcart license fell from $15 to $4 and by 1904 there were 6,747 push-cart peddlers in New York City."

Another article from The Museum at Eldridge Street claims that in 1900 there were 25,000 pushcarts.
https://www.eldridgestreet.org/history/pushcarts-the-hustle-to-the-american-dream/

Perhaps 6,747 were licensed, and the rest not?

A 1903 article in The NY Sun (found at www.fultonhistory.com)  titled "The Plague of Pushcarts" states that to get a NYC pushcart license one had to show "first papers" towards naturalization, but that many newcomers used other peoples papers.

Regards,

Sherri Bobish