During the preparatory philosophical courses, Rotteck got to know the first Protestant professor of the university, Johann Georg Jacobi, whose teaching and society were major influences on him.
Having from early childhood an interest in historical studies, especially biography, he applied in 1798 for the vacated office of professor of history at the University of Freiburg and received it.
In those times, the frankness with which he expressed himself and his spirited idealism compensated for his lack of objective historical knowledge, without which later no beginner would think of trying for a teaching position, to say nothing of being allowed to fill it for 20 years.
After some time, Rotteck was no longer contented with the relatively small public provided by his lecture hall, and in 1812 he began to publish his Allgemeine Geschichte, which passed through many editions in Germany and was available in translation the world over.
He only aimed to take the historical knowledge at hand and through an appropriate treatment make it accessible to the layperson and not only to enrich the reader of average education but also strengthen the moral will, and especially influence the character and attitude of young people coming of age.
Rotteck appealed to the flawless vigor of the life of the people, to the love of freedom and fatherland; he alluded to equalizing justice in the development of nations.
In contrast to the oppressive attitude of the German governments which so sorely disappointed the fighters in the war of liberation, the pathos of Rotteck's presentation of history, its exaltation of the free development of the spirit of the people, the fight for justice and self-determination over willfulness and tyranny, found a genuinely thankful and enthusiastic public.
In this field as well, his inclination to practical achievement felt the need to spread his teaching beyond the walls of his lecture hall, and from 1829 to 1836, he published in four volumes his Primer of political science and rational law (German: Lehrbuch der Staatswissenschaften und des Vernunftrechts) which in his mind promised to outdo the almost unprecedented success of his world history in its effect on contemporary public opinion.
Nevertheless Rotteck's judgement on the questions of the day still had great influence, especially after he founded his organ, the Allgemeine politischen Annalen, where he commented on all worldly affairs from his pulpit of the liberal point of view.
At the instance of the Bundestag, the publication of Die Freisinnige was suspended and the Annals were forbidden and Rotteck was prohibited from issuing a similar journal for the next five years.
For a generation, the German middle class, which gravitated toward these ideas, looked for and found explanations on all questions of political life in this work, until the dissimilar, though more solid, Staatswörterbuch of Johann Caspar Bluntschli and Karl Brater superseded it.
Although his writings found a following in Europe and the world, Rotteck's practical political accomplishments were primarily devoted to the Grand Duchy of Baden, into which, in consequence of the Peace of Pressburg, his home of Breisgau had been incorporated.
Contrary to Rotteck's desires, the government, which during the elections for 1825 and 1828 successfully exercised all its options to derail the opposition, impeded his entrance into the second chamber.
From 1831 until his death, Rotteck belonged to the second chamber of the Baden diet, and during these nine years he tirelessly worked for the promotion of political and economic matters which were close to his heart.
At the diet of 1833, he poured out his full measure of scorn when a decree of the German Confederation dictated an early end for the youthful Baden press freedom.
When the Baden ministry, which had obeyed a mighty pressure from Prussia and Austria when it had revoked the liberal press law, saw a vote of no confidence in a resolution put forward by Rotteck for the preservation of the law and rejected it as slanderous, Rotteck made a resolution for the naming of a commission which would assess the condition of the fatherland and afterward lay appropriate legislation before the second chamber.
Somewhat earlier, at the beginning of 1833, to a certain extent as an answer to the dismissal of Rotteck from his teaching position, his home town of Freiburg elected him as mayor.
Thus in the diet of 1837 he resisted with much determination the government's suggestion of division of the electorate into classes after a census, since this contradicted what he saw as a just principle of the absolute equality of all citizens.