I previously looked at the settlement of property rights from the the English Civil wars to the Glourious Revolution and I don't know where to look for the US. I am English and therefore I do not know anything about US law or how state/federal law interacts (other than interstate trade is regulated by the federal government).
A slightly longer version of my question is:
Other than the obvious exemption for slave contracts could a person formerly resident in a Confederate state use the US court system to enforce a contract; court ruling or change in train of property made whilst they/their state was in rebellion?
Also
We're judgements made in criminal courts considered part of the common law, or were all judgment rendered void?
In 1869 the Supreme Court took up this question in the case Texas v. White. After adopting its Ordinance of Secession, Texas had sold United Treasury Bonds to raise revenue for "defence". The US Treasury didn't consider such a sale valid. The postwar Governors of Texas adopted the same reasoning and sued the brokerage firm for compensation. The Supreme Court ruled that secession was invalid, and that therefore all subsequent acts of the legislature were unlawful. However, the court acknowledged that the unlawful government of Texas was the only existing government in from secession until the end of the Civil War and that therefore not all acts could or should be invalidated. The most relevant part of the opinion by Chief Justice Chase said:
"It may be said, perhaps with sufficient accuracy, that acts necessary to peace and good order among citizens, such for example, as acts sanctioning and protecting marriage and the domestic relations, governing the course of descents, regulating the conveyance and transfer of property, real and personal, and providing remedies for injuries to person and estate, and other similar acts, which would be valid if emanating from a lawful government, must be regarded in general as valid when proceeding from an actual, though unlawful government; and that acts in furtherance or support of rebellion against the United States, or intended to defeat the just rights of citizens, and other acts of like nature, must, in general, be regarded as invalid and void."
The Supreme Court ruled that the bond sale was invalid because it was made to further rebellion.
So to address your question (and TL;DR) it depends on the purpose of the contract, or property sale, court judgement, etc. If it was made to further rebellion no. But otherwise, all those things were considered valid.
Source: Texas v. White, 74 U.S. 700 (1868) (https://supreme.justia.com/cases/federal/us/74/700/)