u cannot do it using sqlplus GUI.
ie by default when u click icon '+ ' it opens sqlplusw.exe
instead use sqlplus.exe from command prompt, which is command line mode.
you can use Uparrow to get the previous command

NOpe.
you cannot 'see' the history.
but you can get back the commands u executed before

use sqlplus.
 
like
c: sqlplus mag/mag@somedb

select .... first query;
select .... second query;
..
..
now hit up arrow key, to browse through the previious commands, one by one. ( just like you do in dos or bash shell!!)