Complex sentence: Latimer's lawyer, Samuel Sewell, sought a writ of personal replevin from Massachusetts Chief Justice Lemuel Shaw, who had strong anti-slavery views, arguing that Latimer should have the right to have his identity determined by a jury.
Split into simpler sentences: Latimer's lawyer, Samuel Sewell, then sought a writ of personal replevin from Massachusetts Chief Justice Lemuel Shaw, who was known to have strong anti-slavery views. Sewell argued that Latimer should have the right to have his identity determined by a jury.