how to align and array I have a mesh and model i want to align it and array it



I want to achieve like this



For that i have made a profile mesh



But for me its getting hard to align i tried with the magnetic tool to snap but for me works do difficult. Any other way or good way to align it and then array with the reference image.
In Editmode, select the face and choose View >> Align View >> Align View to Active. 'Top' usually works. 

Next add a cube and put the checkmark on 'Align to View' in the redo Panel to the left ( or F6). Back in medieval days, objects were aligned to view by default.

Now you can copy the cube's rotation for your stone.

By the way: the original wall in the picture is vertical, no need to align anything.