National Bank and Trust Co. _v._ Chicago, R.I. and P.R. Co.,[1094] where Justice Sutherland wrote, on behalf of a unanimous court: "* * * these acts, far-reaching though they may be, have not gone beyond the limit of Congressional power; but rather have constituted extensions into a field whose boundaries may not yet be fully revealed."[1095] CONSTITUTIONAL LIMITATIONS ON THE POWER In the exercise of its bankruptcy powers Congress must not transgress the Fifth and Tenth Amendments. It may not take from a creditor specific property previously acquired from a debtor nor circumscribe the creditor's right to such an unreasonable extent as to deny him due process of law;[1096] neither may it subject the fiscal affairs of a political subdivision of a State to the control of a federal bankruptcy court.[1097] Since Congress may not supersede the power of a State to determine how a corporation shall be formed, supervised and dissolved, a corporation which has been dissolved by a decree of a State court may not file a petition for reorganization under the Bankruptcy Acts.[1098] But Congress may impair the obligation of a contract and may extend the provisions of the bankruptcy laws to contracts already entered into at the time of their passage.[1099] It may also empower courts of bankruptcy to entertain petitions by taxing agencies or instrumentalities for a composition of their indebtedness where the State has consented to the proceeding and the federal court is not authorized to interfere with the fiscal or governmental affairs of the petitioner.[1100] Also bankruptcy legislation must be uniform, but the uniformity required is geographic, not personal. Congress may recognize the laws of the States relating to dower, exemption, the validity of mortgages, priorities of payment and similar matters, even though such recognition leads to different results from State to State.[1101] THE POWER NOT EXCLUSIVE