He was the son of Abraham Augustus Abendroth, a lower court procuration from Eisenberg, Saxony.

After having lived for a number of years as a lawyer in Hamburg, where he helped to administer the newly founded Armen-Anstalt (Poor's Institution), he was elected alderman on 5 September 1800.

In this capacity he held the office of praetor – meaning mayor – during the French occupation.

The praetor was the first instance for civil cases and led the fact-finding actions when required.

After the end of the occupation and his return to Hamburg, Abendroth became head of the police, as successor of his brother-in-law Johann Heinrich Bartels, and once more helped in the Armen-Anstalt.