When Adolf Hitler was still a corporal in the German army, he was ordered to spy on the DAP during one of its meetings at the Sterneckerbräu on 12 September 1919.

Hitler was very good at making speeches, so  Anton Drexler asked him to join the party.
Hitler thought about this, and then joined near the end of September 1919.
There were no membership numbers or cards when Hitler joined the party.
In January 1920 the DAP began to give membership cards and numbers.
 They started at number 501 to make the party look bigger.
 Hitler got number 555, but he was also committee member number 7.
 Later Hitler said he  was party member number 7, to make it look like he was a founder member of the DAP.
When Adolf Hitler was still a corporal in the German army, he was ordered to spy on the DAP during one of its meetings at the Sterneckerbräu on 12 September 1919.
Hitler was very good at making speeches, so  Anton Drexler asked him to join the party. Hitler thought about this, and then joined near the end of September 1919. There were no membership numbers or cards when Hitler joined the party. In January 1920 the DAP began to give membership cards and numbers.  They started at number 501 to make the party look bigger.  Hitler got number 555, but he was also committee member number 7.  Later Hitler said he  was party member number 7, to make it look like he was a founder member of the DAP.
German Workers' Party