<P> The bagel came into more general use throughout North America in the last quarter of the 20th century with automation . Daniel Thompson started work on the first commercially viable bagel machine in 1958 ; bagel baker Harry Lender , his son , Murray Lender , and Florence Sender leased this technology and pioneered automated production and distribution of frozen bagels in the 1960s . Murray also invented pre-slicing the bagel . </P>
when did bagels become popular in the us
in the last quarter of the 20th century