The Assessors v. Osbornes was a case heard by the United States Supreme Court in 1869. The case involved a dispute between the Osbornes, a family of landowners in New York, and the assessors of the town of Newburgh, New York. The Osbornes had refused to pay taxes on their property, arguing that the assessment was too high and that the assessors had not followed the proper procedures in assessing the property. The assessors argued that the assessment was fair and that the Osbornes had not followed the proper procedures in challenging the assessment. The Supreme Court ruled in favor of the Osbornes, finding that the assessors had not followed the proper procedures in assessing the property. The Court held that the assessors had failed to provide the Osbornes with a written notice of the assessment, as required by New York law. The Court also held that the assessors had failed to provide the Osbornes with an opportunity to be heard before the assessment was made. As a result, the Court held that the assessment was invalid and that the Osbornes were not required to pay the taxes.

In The Assessors v. Osbornes, the Supreme Court was asked to decide whether a state could tax federal bonds owned by its citizens. The majority opinion held that states do not have the power to impose taxes on federally-issued securities, as this would be an unconstitutional interference with Congress’s exclusive authority over such matters. However, Justice Field dissented from this ruling and argued that while it is true that Congress has exclusive control over taxation of federal securities, nothing in the Constitution prevents a state from taxing property within its borders regardless of ownership or origin. He further noted that if states were prohibited from taxing these types of assets then they would be unable to raise revenue for essential public services like education and infrastructure improvements without relying solely on direct taxation which he believed was unfair and unjustified given how much money individuals can make through investing in government bonds. In conclusion, Justice Field argued against his colleagues' decision because he felt it denied states their right to collect necessary funds for public purposes without infringing upon Congressional powers