A member of the Democratic Party, Chamberlain ran for the Oregon House of Representatives in November 1880, winning election to a two-year term.

In 1884, Chamberlain was named district attorney for Oregon's 3rd judicial district.
His skill in that position gained the notice of Democratic Governor Sylvester Pennoyer and when in 1891 the state legislature established the new position of Oregon Attorney General, Chamberlain was appointed in May as the first to serve that position.
He stood for election to the position in the fall, winning at the polls despite being the candidate of the minority party in the state.
Chamberlain would remain Oregon's Attorney General until January 1895, following the expiration of his term.
He would be the only Democrat to serve that position for 58 years, until Robert Y. Thornton was elected in 1952.

After leaving the Oregon Attorney General's position, Chamberlain went into the banking business, taking positions with the First National Bank and later the Linn County National Bank in his new hometown of Albany.

Chamberlain next moved north to Portland and in 1900 stood for election as the district attorney for Multnomah County.
He won a more than 1,000 votes, despite the county's 4,000 person Republican majority.
This again put Chamberlain in the public eye for a run at statewide office.
A member of the Democratic Party, Chamberlain ran for the Oregon House of Representatives in November 1880, winning election to a two-year term.
In 1884, Chamberlain was named district attorney for Oregon's 3rd judicial district. His skill in that position gained the notice of Democratic Governor Sylvester Pennoyer and when in 1891 the state legislature established the new position of Oregon Attorney General, Chamberlain was appointed in May as the first to serve that position. He stood for election to the position in the fall, winning at the polls despite being the candidate of the minority party in the state. Chamberlain would remain Oregon's Attorney General until January 1895, following the expiration of his term. He would be the only Democrat to serve that position for 58 years, until Robert Y. Thornton was elected in 1952.
After leaving the Oregon Attorney General's position, Chamberlain went into the banking business, taking positions with the First National Bank and later the Linn County National Bank in his new hometown of Albany.
Chamberlain next moved north to Portland and in 1900 stood for election as the district attorney for Multnomah County. He won a more than 1,000 votes, despite the county's 4,000 person Republican majority. This again put Chamberlain in the public eye for a run at statewide office.
George Earle Chamberlain