During revolutions in 1848-1849, the Frankfurt Parliament had produced a constitution for a unified Germany, but that move was rejected at the time by the king of Prussia, to whom the constitution was offered.
300 German states = before unification
The German states had a long history of sovereignty in their individual territories. Unification meant bringing all those states together into one national entity.
trade facilitated in the region = before unification
The Zollverein, or customs union, was created between the German states in the 1830s. This eliminated customs tariffs between states and was a step that began moving in the direction of unification.
risk of French aggression = before unification
Germany became a united empire after the Franco-Prussian War of 1870-71. Victory over France in that war by the German states operating as a coalition was part of what brought about unification.
boundaries changed by Napoleon = before unification
When Napoleon conquered territories throughout Europe in the early 1800s, he rearranged borders to enhance his empire's management of conquered territories. In the German states, this made them work together in ways they had not before, and was a catalyst toward desires for unification.
two-house legislature = after unification
There was a legislature in the North German Confederation (1867-1870), which preceded unification. But that was a single-house (unicameral) parliament, whereas the Reichstag (legislature) of the unified German Empire was bicameral.
