Between 1924 and 1928, Hitler focused on rebuilding and strengthening the Nazi Party. This was a necessary step after the failure of the Beer Hall Putsch in 1923 in which Hitler mounted a coup in a beer hall in Bavaria. For this, Hitler was convicted of treason and served nine months in prison - an event which threatened to bring about the Party's demise. As a result, Hitler left prison and immediately began this rebuilding programme.
One of the first items on the agenda was to declare himself the Fuhrer (leader) of the Party which he did in Munich in 1925. In the same year, he published his infamous autobiography, Mein Kampf, which provided the Party's ideological basis.
As the Party's popularity grew, Hitler set up a number of smaller groups, like The Hitler Youth, to further spread his message. Similarly, in 1927, the Party held its first political rally in Nuremberg which boosted Party membership to over 10,000 people (See the first reference link provided). In 1928, however, the Party performed poorly in the Reichstag elections, receiving only 2.6% of the vote - which prompted Hitler to appoint Joseph Goebbels as his chief of propaganda. (See the second reference link provided).
In late 1924, Hitler was released from prison and reestablished the Nazi Party. This version of the party was meant to be less violent and revolutionary. It became part of the political system and competed in elections across the country.
During the time period you mention, though, the Nazis never did well in national elections. They got very small percentages of the vote. During this time, all that they were really doing was becoming more organized. They were creating a hierarchical organization with block leaders and cell leaders and county leaders and regional leaders, culminating at the top with Hitler. They were also recruiting more members in certain parts of the country where economic conditions were still poor.
By developing their organization and recruiting as much as possible, they were in position to become much more of a force when the Great Depression ruined Germany's economy.
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