how do i increase the size of this SVG?

http://upload.wikimedia.org/wikipedia/commons/a/a5/Map_of_USA_with_state_names.svg

is it possible to increase the size of this map?

Yes. As you know, SVG files are vector images, so you can simply zoom in when you view it.

But if you want to change the default size, then you can replace

<svg 
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:cc="http://creativecommons.org/ns#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   version="1.0"

   width="958.69"
   height="592.78998"

   id="svg2275"
   sodipodi:version="0.32"
   inkscape:version="0.46"
   sodipodi:docname="Map of USA with state names.svg"
   sodipodi:docbase="C:\temp\webdesign"
   inkscape:output_extension="org.inkscape.output.svg.inkscape"> 

with

<svg 
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:cc="http://creativecommons.org/ns#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   version="1.0"

   width="1917.38"
   height="1185.57996"
   viewBox="0 0 958.69 592.78998"

   id="svg2275"
   sodipodi:version="0.32"
   inkscape:version="0.46"
   sodipodi:docname="Map of USA with state names.svg"
   sodipodi:docbase="C:\temp\webdesign"
   inkscape:output_extension="org.inkscape.output.svg.inkscape"> 

That is, you define the viewBox (to 0, 0, <oldWidth>, <oldHeight>), and then you can set the width and height as you wish. The above example thus doubles the width and height.