His early publications promoted liberal views and satirized famous politicians leading up to the German revolutions of 1848–49, resulting in government censorship and earning him a short prison stay in 1852.

He then developed Die Gartenlaube, a weekly illustrated magazine aimed at enlightening and entertaining the whole family, particularly the middle and lower classes of society.

He apprenticed at the book publishing firm Hofbuchhandlung Hoffmann in Weimar, which was closely connected with the intellectual royal court of Karl August, Grand Duke of Saxe-Weimar-Eisenach.

Keil employed eminent writers from the democratic and liberal spectrum, including Robert Blum, Johann Jacoby, Gustav Adolf Wislicenus, Ernst Dronke, and Leberecht Uhlich.

It was the first popular expression of an awakened intellectual political movement in Germany and soon became the most important publication during the Vormärz, the period preceding the German revolutions of 1848–49.

[5] Lighthouse often espoused radical political views and its steel-engraved illustrations satirized famous politicians, resulting in incessant persecutions by the police and forcing Keil to frequently change publishing locations: first to Zeitz, then Magdeburg, Halle, Dessau, Bremen and finally Braunschweig.

[7][8] He envisioned an illustrated weekly that would provide "intellectual exercise and education as entertainment" and serve as a "people's encyclopedia" covering a wide range of interests.

Each edition would contain features by famous writers, essays on German and foreign customs, articles on science and nature, a section on human health, and a feuilleton of non-political news, art, and literary criticism.

Initially he could not serve as editor because his press credentials had been revoked and he was still under police surveillance, so he borrowed the firm of Stolle & Diezmann for the first run of 5000 copies.

[4] His objective was to reach and enlighten the whole family, especially the German middle classes, through a carefully crafted mixture of current events, essays on the natural sciences, biographies, short stories, poetry, and full-page illustrations.

Over time he attracted known naturalists, scientists and technicians such as Karl Ernst Bock, Carl Vogt, Emil Adolf Rossmässler and Max Maria von Weber to his pages, turning the Gartenlaube into a major vehicle of popular science in Germany.

[11] In the literary field he employed Hermann Schmidt, Theodor Storm, Gottfried Keller, Levin Schücking and novelist Wilhelm Raabe, among others.

[4] Circulation reached 382,000 by 1875, and because Gartenlaube was common family reading with many public cafes taking delivery, estimates of actual readership run between two[1] and five million.

[4] On the pages of Die Gartenlaube, Keil published countless articles on culture, politics, landscape, industry, technology, history, and other topics directed at all segments of German society.