If you have a Foreign Driving License (not necessary International), I know you can still drive in US.
1 year in Marlyand.(I am sure off)....but rules depends from State to State!!
About getting a DL, you need Address proof, if you have your documents, i see why won't they issue a DL. [we'll someone undocumented can get it why not you]
Validation: vary from State to State.
For DC : you don't need to appear for Written or Road test,[ just proof of Foreign/Other State License and DC residence(address) is required.]
catch for DC is you need Social Security number!!
The written
test is not required if your prior license is valid or has not
been expired for more than 90 days. The road test is not required
if your prior license is valid or has not been expired for more
than 180 days. http://dmv.dc.gov/serv/dlicense/DL_os_convert.shtm
