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Which territories did Prussia annex after the Seven Weeks' War of 1866?

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Historical map showing the unification of Germany by Prussia in the late 19th century. The map highlights in green the Kingdom of Prussia as of 1866, and in yellow the additional territories that formed the German Empire by 1871-1918, encompassing most of north-central Europe. Neighboring countries such as France, Belgium, the Netherlands, Denmark, Sweden, Russia, Austria-Hungary, and Switzerland are labeled, with major regions and states within the empire clearly marked. — Prussia The unification of Germany by Prussia, which brought most of north-central Europe into one kingdom.

Following the Prussian victory in the Seven Weeks' War of 1866, the Treaty of Prague formalized the annexation of several territories into the Prussian state. These acquisitions allowed Prussia to connect its eastern and western provinces, consolidating its control over the northern two-thirds of Germany.12

The territories annexed by Prussia were:

Schleswig-Holstein12
Hanover12
Hesse-Kassel (also referred to as Electoral Hesse)13
Nassau12
Frankfurt am Main12

This expansion significantly increased Prussia's population and territorial reach, providing the foundation for the subsequent formation of the North German Confederation under Prussian leadership.12