Henry Marsh welcomes parking beside US city - little money is needed (9)
I believe the answer is:
halfpenny
'beside us city little money is needed' is the definition.
I can't judge whether this definition defines the answer.
'henry marsh welcomes parking' is the wordplay.
'henry' becomes 'hal'.
'marsh' becomes 'fenny' (I am not sure about this - if you are sure you should believe this answer much more).
'welcomes' is an insertion indicator (in sense of 'invites in').
'parking' becomes 'p'.
'fenny' enclosing 'p' is 'fpenny'.
'hal'+'fpenny'='HALFPENNY'
Can you help me to learn more?
(Other definitions for halfpenny that I've seen before include "Old coin, 24 to a shilling" , "Four hundred and eighty such in one pound, once" , "Former coin" .)