This case was a dispute between Slidell and Grandjean, Deputy Surveyor of the United States, over a land dispute in Louisiana. Slidell claimed that he had purchased a tract of land from the United States in 1845, and that the land had been surveyed by Grandjean in 1846. Slidell argued that the survey was inaccurate and that he was entitled to additional land. Grandjean argued that the survey was accurate and that Slidell was not entitled to any additional land. The Supreme Court held that Slidell was entitled to additional land, as the survey was inaccurate. The Court found that the survey was not conducted in accordance with the requirements of the Land Act of 1820, and that Slidell was entitled to additional land as a result. The Court also held that Slidell was entitled to damages for the inaccurate survey. The Court's decision was significant because it established that the United States was liable for inaccurate surveys and that individuals were entitled to damages for such surveys. The decision also established that individuals were entitled to additional land if the survey was inaccurate.

In Slidell & Another v. Grandjean, Deputy Surveyor of the United States, the Supreme Court was asked to decide whether a survey made by an officer of the United States in 1845 could be used as evidence in a dispute over land titles. The majority opinion held that it could not because it had been made without proper authority and did not comply with certain legal requirements. However, Justice Field dissented from this decision on two grounds: firstly, he argued that even if there were irregularities or errors in the survey itself they should have no bearing on its validity; secondly, he maintained that since Congress had accepted and acted upon such surveys for many years prior to this case then those surveys must be considered valid regardless of any technical defects which may exist within them. In conclusion therefore Justice Field believed that despite any potential flaws present within it, this particular survey should still be allowed as evidence due to its long-standing acceptance by Congress and other government bodies.