great lakes dredge dock huffman argued decided may emmett kerrigan new orleans petitioners perrault baton rouge respondents chief justice stone delivered opinion petitioners brought suit district respondent state officer charged administration enforcement louisiana unemployment compensation law act amended act act first extraordinary session acts complaint alleges petitioners numerous classes employees engaged navigation operation dredges pile drivers operation quarter boats tugs launches barges vessels used deepening dredging extending otherwise improving channels underlying navigable waters state tax contribution state unemployment insurance fund state law exact petitioners exceeded suit brought sum relief prayed declaratory judgment state law applied petitioners employees unconstitutional void trial district held statute applicable petitioners employees applied valid exercise state power formal judgment ordered dismissal suit interpreted light opinion findings conclusions law metropolitan water kaw valley drainage gulf refining clark williard american propeller mfg interpreted rests wholly declaration statute applied petitioners constitutional thus effect declaratory judgment appeals fifth circuit affirmed holding statute exacting employers contributions state unemployment compensation fund valid exercise state taxing power see steward mach davis carmichael southern coal coke application act petitioners interfere characteristic feature general maritime law interstate international aspects fall ban southern pac jensen ann cases following federal social security act exempting operation officers crews vessels field otherwise precluded state applying law respect employees question public importance questions decided granted certiorari set case argument standard dredging corporation murphy international elevating murphy appeal order granting writ requested counsel discuss briefs oral argument question whether declaratory judgment procedure appropriately used case complaint seeks judgment state officer prevent enforcement state statute state act held exacts employers payments state unemployment insurance fund nature excise tax upon exercise right privilege employing individuals measured percentage wages paid see carmichael southern coal coke supra petitioners challenged state right collect tax interposed barrier collection present suit federal declaratory judgment district indicated substance given declaratory judgment circuit appeals sustained save purpose courts occasion entertain suit pronounce judgment neither parties questioned sufficiency pleadings present case declaratory judgment without raising issue pass question submitted counsel whether declaratory judgment procedure may appropriately resorted circumstances case answering nature remedy afforded taxpayers state law illegal exaction tax importance section article constitution louisiana directs legislature shall provide issuance process restrain collection tax complete adequate remedy prompt recovery every taxpayer illegal tax paid act sets complete statutory scheme carry effect constitutional provision courts state forbidden restrain collection state tax person aggrieved payment amount found due enforcement provision laws relation thereto shall pay tax appropriate state officer file suit recovery either state federal courts pending suit amount collected required segregated held subject judgment rendered suit taxpayer prevails suit interest two per cent per annum added amount taxes refunded recognized federal courts exercise sound discretion traditionally guided courts equity granting withholding extraordinary relief may afford ordinarily restrain state officers collecting state taxes state law affords adequate remedy taxpayer matthews rodgers withholding extraordinary relief courts authority give denial jurisdiction congress conferred federal courts settled rule measure inadequacy plaintiff legal remedy legal remedy afforded federal state courts stratton louis di giovanni camden fire ins contrary recognition jurisdiction conferred federal courts embraces suits equity well law federal equity may appropriate case refuse give special protection private rights exercise jurisdiction prejudicial public interest dern virginian ry system federation stay hand public interest reasonably appears private interests suffer see commonwealth pennsylvania williams cases cited public interest federal courts equity exercise discretionary power grant withhold relief avoid needless obstruction domestic policy scrupulous regard rightful independence state governments times actuate federal courts proper reluctance interfere injunction fiscal operations require relief denied every case asserted federal right may preserved without whenever question presented uniformly held mere illegality unconstitutionality state municipal tax ground equitable relief courts remedy law plain adequate complete aggrieved party left remedy state courts cause may brought review federal question involved matthews rodgers supra pages pages interference state internal economy administration inseparable assaults federal courts validity state taxation necessarily attends injunctions interlocutory final restraining collection state taxes considerations moment persuaded federal courts equity deny relief state acting within constitutional authority set adequate procedure securing taxpayer recovery illegally exacted tax congress recognized gave sanction practice federal equity courts act august stat enacted amendment section judicial code provides district shall jurisdiction suit enjoin suspend restrain assessment levy collection tax imposed pursuant laws state plain speedy efficient remedy may law equity courts state earlier refusal federal courts equity interfere collection state taxes unless threatened injury taxpayer one state courts afford adequate remedy confirmation practice congress important bearing upon appropriate use declaratory judgment procedure federal courts means adjudicating validity state taxes true act congress speaks suits enjoin suspend restrain assessment levy collection tax imposed state law declaratory judgment procedure may case used procure determination rights parties without injunction coercive relief also true procedure may every practical sense operate suspend collection state taxes litigation ended find unnecessary inquire whether words statute may construed prohibit declaration federal courts concerning invalidity state tax opinion considerations led federal courts equity refuse enjoin collection state taxes save exceptional cases require like restraint use declaratory judgment procedure statutory authority render declaratory judgments permits federal courts new form procedure exercise jurisdiction decide cases controversies law equity judiciary acts already conferred aetna life ins haworth thus federal declaratory judgments act act june stat amended provides subdivision declaration rights may awarded although relief asked subdivision relief based declaratory judgment decree may granted whenever necessary proper jurisdiction district present suit praying adjudication rights anticipation threatened infringement analogous equity jurisdiction suits quia timet decree quieting title see nashville ry wallace called upon adjudicate essentially equitable cause action district free suit equity grant withhold relief prayed upon equitable grounds declaratory judgments act devised deprive courts equity powers freedom withhold relief upon established equitable principles provided new form procedure adjudication rights conformity principles senate committee report bill pointed exercise equity power make rules governing declaratory judgment procedure house report declared discretion conferred upon courts whether administer justice procedure see brillhart excess ins borchard declaratory judgments ed considerations persuaded federal courts equity grant relief allegedly unlawful state tax led enactment act august persuasive relief way declaratory judgment may likewise withheld sound discretion due regard considerations duty withhold relief present case appears state legislature provided payment challenged tax appropriate state officer taxpayer may maintain suit recover back suit may assert federal rights secure review affords adequate remedy taxpayer time leaves undisturbed state administration taxes act august predicated upon desirability freeing interference federal courts state procedures authorize litigation challenging tax tax paid see sess sess even though statutory command deemed restricted prohibition injunctions restraining collection state taxes enactment hardly indication disapproval policy federal equity courts mandatory withdrawal traditional power decline jurisdiction exercise discretion like reasons think plain also enactment act august stat excluded operation declaratory judgments act cases involving federal taxes taken deprive courts discretionary authority withhold declaratory relief appropriate cases amendment passed merely purpose clear declaratory judgments act permit radical departure policy congress require prompt payment federal taxes see sess judgment dismissal must therefore affirmed solely ground appropriate exercise discretion relief way atory judgment denied without consideration merits affirmed