Knishes can be purchased from street vendors in urban areas with a large Jewish population, sometimes at a hot dog stand or from a butcher shop. It was made popular in North America by Eastern European immigrants (mainly Polish).
Knishes may be round, rectangular, or square. They may be entirely covered in dough or some of the filling may peek out of the top. Sizes range from those that can be eaten in a single bite hors d'oeuvre to sandwich-sized.
Eastern European immigrants who arrived sometime around 1900 brought knishes to North America. Knish (קניש) is a Yiddish word that was derived from the Ukrainian or Russian "knysh" (Кныш), meaning dumpling or cake. The first knish bakery in America was founded in New York in 1910." Generally recognized as a food made popular in New York by immigrants in the early 1900s, the United States underwent a knish renaissance in the 2000s driven by knish specialty establishments such as the Knish Shop in Baltimore, Maryland, Buffalo and Bergen in Washington, DC, or My Mother's Knish, in Westlake Village, California.