One major success was Bismarck's constitution itself. Pressured by German liberals to create a constitutional government after the unification of the country in the wake of the Franco-Prussian War, Bismarck created a government that would guarantee him practical control of Germany for years to come. He created a bicameral legislature in which the people's representatives, housed in the Reichstag, were balanced by the German nobles in the Bundesrat. But most important was that Bismarck himself would be Chancellor, which, according to the constitution, meant he could only be removed from power by the emperor himself. This, along with the considerable powers of the office, gave him enormous influence over the direction of the new German state.
A failure of Bismarck's tenure was the so-called Kulturkampf, his political attack on Catholics within the German state. Justified in the minds of Bismarck and other Germans by the proclamation of papal infallibility by Pope Pius IX in 1870, this was an attempt to marginalize the role of the Catholic Church. Bismarck's effort failed in most parts of German, except those regions where the Catholic Church was already marginal. He was forced, as a consequence, to enter into a political alliance with Catholics, an eventuality that did not cause Bismarck, ever the opportunist, much consternation.
Source: McKay, Hill, and Buckler, A History of Western Society, 7th edition. (New York: Houghton Mifflin, 2003) 839.