[4][5] As U.S. Attorney, Goodwin prosecuted many individuals for violations of the Neutrality Act of 1794 during the Patriot War of 1837 and 1838, in which bands of U.S. citizens invaded Upper Canada to harass British troops stationed there.

These prosecutions were unpopular, leading to threats against Goodwin, who was for a time given protective accompaniment by friends including General Hugh Brady and explorer Robert Stuart.

However, witnesses were uncooperative and Judge Wilkins consistently sustained defense objections, ultimately dismissing the case.

[3] Goodwin was president of the Constitutional Convention of 1850,[4] and also took part in the prosecution of the famous railroad conspiracy case in Detroit that year, in which Governor Seward was the leading counsel for the defense.

[4] In 1851, Goodwin was elected a circuit judge in the Upper Peninsula, and was thereafter continuously re-elected until 1881, serving for thirty years[3] He was also a member of the Constitutional Convention 1867.