A fence panel construction device includes a structural member and a pair of post members coupled to the structural member. Each post member includes a pair of attachment devices configured to removably attach a pair of fence stringers to the pair of post members. A pair of actuator mechanisms are coupled to a respective one of the pair of post members to position the pair of post members corresponding to a pair of fence posts on a property. A finishing assembly is coupled to the structural member and includes at least one fastening device and at least one trimming device both operable to move vertically. The finishing assembly is operable to move horizontally while the at least one fastening device fastens fence boards to the pair of fence stringers and at least one trimming device trims the fence boards. A method of making a fence panel is provided.