Constrain a line to be horizontal or vertical in a drawing (not in a sketch in a part studio!)

monroe_weber_shirk

I am creating/editing a title block in a drawing. I need to move some lines and I can't find a method to edit a line without giving it a slight angle. How do I constrain the lines? I see them snap to other lines to get the endpoint on the right line, but I don't see how to force the lines to be horizontal or vertical.

I see the horizontal and vertical inferencing lines, but they disappear as I approach the line that I want to snap to.

monroe_weber_shirk

I discovered that when I create a new line that there is a perpendicular inference. The perpendicular inference doesn't show up when editing an existing line.