[1] Thanks to the Catholic bishop Daniel Bonifacius von Haneberg, the abbot of St. Boniface's Abbey, he met the publicist and politician Josef Edmund Jörg [de].

[2] Thanks to Jörg, he worked for the Volksbote für den Bürger und Landmann and the Straubinger Tagblatt in 1865 before becoming a war correspondent in Bohemia in 1866.

[1] On 1 April 1869, he founded his own Catholic-Bavarian newspaper, Das Bayerische Vaterland,[1] which soon became known and popular in the Kingdom of Bavaria for its open criticism of the Chancellor of Germany and the German Empire's policies.

[2] Due to the high cost of the Franco-Prussian War of 1870–71 he called the new German Empire's crown a "bigger Prussian Pickelhaube".

He was sentenced to nine months imprisonment but was able to force the ministry to prove its role and procedures at great length.

[2] In 1879, the Catholic diocese of Munich called for the newspaper to be boycotted after Sigl attacked the new archbishop Antonius von Steichele.