Question

why did the franks have to go in hiding

Answer 1

Anne Frank's Family Goes into Hiding. In early July 1942, after Margot Frank received a letter ordering her to report to a work camp in Germany, AnneFrank's family went into hiding in an attic apartment behind Otto Frank'sbusiness, located at Prinsengracht 263 in Amsterdam.

Answer 2

The Nazi presence in Amsterdam causes Mr. Frank to discuss leaving their home and going into hiding. Jews are being forced into concentration camps. None-the-less, the Frank's decision to move into the annex is accelerated because Margot, a sixteen year old, was called up by the SS.