Mühsam moved to Berlin in 1900, where he soon became involved in a group called Neue Gemeinschaft (New Society) under the direction of Julius and Heinrich Hart which combined socialist philosophy with theology and communal living in the hopes of becoming "a forerunner of a socially united great working commune of humanity."
 Within this group, Mühsam became acquainted with Gustav Landauer who encouraged his artistic growth and compelled the young Mühsam to develop his own activism based on a combination of communist and anarchist political philosophy that Landauer introduced to him.
 Desiring more political involvement, in 1904, Mühsam withdrew from Neue Gemeinschaft and relocated temporarily to an artists commune in Ascona, Switzerland where vegetarianism was mixed with communism and socialism.
 It was here that he began writing plays, the first Die Hochstapler (The Con Men), juxtaposing new modern political theory within traditional dramatic forms, which became a typical trademark of his dramatic work.
 During these years, Mühsam began contributing to and editing several anarchist journals.
 These writings made Mühsam the target of constant police surveillance and arrests as he was considered among the most dangerous anarchist agitators in Germany.
 The press seized the opportunity to portray him as a villain accused of anarchist conspiracies and petty crimes.

In 1908, Mühsam relocated to Munich, where he became heavily involved in cabaret.
 While Mühsam did not particularly care for his work in writing cabaret songs, it would become among his most famous creations.

In 1911, Mühsam founded the newspaper, Kain (Cain), as a forum for anarcho-communist ideologies, stating that it would "be a personal organ for whatever the editor, as a poet, as a citizen of the world, and as a fellow man had on his mind."
 Mühsam used Kain to ridicule the German state and what he perceived as excesses and abuses of authority, standing out in favour of abolishing capital punishment, and opposing the government's attempt at censoring theatre, and offering prophetic and perceptive analysis of international affairs.
For the duration of World War I, publication was suspended to avoid government-imposed censorship often enforced against private newspapers that disagreed with the imperial government and the war.

Mühsam married Kreszentia Elfinger (nickname Zenzl), the widowed daughter of a Bavarian farmer, in 1915.

World War I would see the international anarchist community starkly divided into pro-war and anti-war positions, some hyper-nationalistically supporting Germany, others desiring that Germany's enemies (the United Kingdom, France, and later the United States of America) would be victorious.
 Mühsam became extremely nationalistic and militant in his support of Germany in the war, writing in his diaries: "And I the anarchist, the anti-militarist, the enemy of national slogans, the anti-patriot and implacable critic of the armament furies, I discovered myself somehow possessed by the common intoxication, fired by an irate passion."
 His public support of the war was seized upon by the state-controlled press for the purposes of propaganda, and by fellow anarchists who felt betrayed.
 However, by the end of 1914, Mühsam, pressured by his anarchist acquaintances renounced his support of the war effort, stating that "I will probably have to bear the sin of betraying my ideals for the rest of my life" and appealing, "Those who comfortably acquiesce and say 'we cannot change things' shamefully desecrate human dignity and all the gifts of their own hearts and brain.
For they renounce without a struggle every use of their ability to overthrow man-made institutions and governments and to replace them with new ones."
 For the rest of the war, Mühsam opposed the war through increased involvement in many direct action projects, including workers strikes, often collaborating with figures from other leftist political parties.
 As the strikes became increasingly successful and violent, the Bavarian state government began mass arrests of anti-war agitato
Mühsam moved to Berlin in 1900, where he soon became involved in a group called Neue Gemeinschaft (New Society) under the direction of Julius and Heinrich Hart which combined socialist philosophy with theology and communal living in the hopes of becoming "a forerunner of a socially united great working commune of humanity."  Within this group, Mühsam became acquainted with Gustav Landauer who encouraged his artistic growth and compelled the young Mühsam to develop his own activism based on a combination of communist and anarchist political philosophy that Landauer introduced to him.  Desiring more political involvement, in 1904, Mühsam withdrew from Neue Gemeinschaft and relocated temporarily to an artists commune in Ascona, Switzerland where vegetarianism was mixed with communism and socialism.  It was here that he began writing plays, the first Die Hochstapler (The Con Men), juxtaposing new modern political theory within traditional dramatic forms, which became a typical trademark of his dramatic work.  During these years, Mühsam began contributing to and editing several anarchist journals.  These writings made Mühsam the target of constant police surveillance and arrests as he was considered among the most dangerous anarchist agitators in Germany.  The press seized the opportunity to portray him as a villain accused of anarchist conspiracies and petty crimes.
In 1908, Mühsam relocated to Munich, where he became heavily involved in cabaret.  While Mühsam did not particularly care for his work in writing cabaret songs, it would become among his most famous creations.
In 1911, Mühsam founded the newspaper, Kain (Cain), as a forum for anarcho-communist ideologies, stating that it would "be a personal organ for whatever the editor, as a poet, as a citizen of the world, and as a fellow man had on his mind."  Mühsam used Kain to ridicule the German state and what he perceived as excesses and abuses of authority, standing out in favour of abolishing capital punishment, and opposing the government's attempt at censoring theatre, and offering prophetic and perceptive analysis of international affairs. For the duration of World War I, publication was suspended to avoid government-imposed censorship often enforced against private newspapers that disagreed with the imperial government and the war.
Mühsam married Kreszentia Elfinger (nickname Zenzl), the widowed daughter of a Bavarian farmer, in 1915.
World War I would see the international anarchist community starkly divided into pro-war and anti-war positions, some hyper-nationalistically supporting Germany, others desiring that Germany's enemies (the United Kingdom, France, and later the United States of America) would be victorious.  Mühsam became extremely nationalistic and militant in his support of Germany in the war, writing in his diaries: "And I the anarchist, the anti-militarist, the enemy of national slogans, the anti-patriot and implacable critic of the armament furies, I discovered myself somehow possessed by the common intoxication, fired by an irate passion."  His public support of the war was seized upon by the state-controlled press for the purposes of propaganda, and by fellow anarchists who felt betrayed.  However, by the end of 1914, Mühsam, pressured by his anarchist acquaintances renounced his support of the war effort, stating that "I will probably have to bear the sin of betraying my ideals for the rest of my life" and appealing, "Those who comfortably acquiesce and say 'we cannot change things' shamefully desecrate human dignity and all the gifts of their own hearts and brain. For they renounce without a struggle every use of their ability to overthrow man-made institutions and governments and to replace them with new ones."  For the rest of the war, Mühsam opposed the war through increased involvement in many direct action projects, including workers strikes, often collaborating with figures from other leftist political parties.  As the strikes became increasingly successful and violent, the Bavarian state government began mass arrests of anti-war agitato
Erich Mühsam