A professional and political ally of Martin Van Buren, among the many elective and appointive positions he held were Attorney General of the United States and United States Attorney for the Southern District of New York.

When fellow Regency member and Van Buren ally Roger Skinner was appointed Judge of the United States District Court for the Northern District of New York in 1819, he sold his law office to Butler, who took over Skinner's clients and pending cases.

[3] Butler began his political career as district attorney of Albany County, serving from 1821 to 1825.

On November 15, 1833, President Andrew Jackson appointed Butler Attorney General, an office he held until 1838.

As one of the leaders of the New York delegation, he supported the candidacy of Martin Van Buren and opposed the 2/3 rule for nominating, but failed in both cases.

In the end, he was the one to announce that the New York delegation would switch to eventual winner James K. Polk.