Rhineland-Palatinate
On 10 July 1945 the occupation authority on the soil of the present-day Rhineland-Palatinate transferred from the Americans to the French. To begin with, the French divided the region provisionally into two "upper presidiums" ("Oberpräsidien"), Rhineland-Hesse-Nassau (for the hitherto Prussian government districts and regions of Koblenz, Trier, and Montabaur) and Hesse-Palatinate (for the hitherto Bavarian Palatinate and old Hessian-Darmstadt province of Rhenish Hesse). The formation of the state was ordained on 30 August 1946, the last state in the Western Zone of Occupation to be established, by Regulation No. 57 of the French military government under General Marie-Pierre Kœnig. It was initially called Rhenish-Palatinate ("Rheinpfälzisches Land" or "Land Rheinpfalz"); the name Rhineland-Palatinate ("Rheinland-Pfalz") was first confirmed in the constitution of 18 May 1947.
Wiesweiler
After the Second World War, the village lay at first within the "Regierungsbezirk" of Koblenz in the then newly founded state of Rhineland-Palatinate. In the course of administrative restructuring in Rhineland-Palatinate in 1968, the "Amt" of Grumbach was dissolved. Wiesweiler passed in 1972 to the then newly founded "Verbandsgemeinde" of Lauterecken, and at the same time also from the "Regierungsbezirk" of Koblenz to the newly founded "Regierungsbezirk" of Rheinhessen-Pfalz (the system of "Regierungsbezirke" in Rhineland-Palatinate has since been abolished).