As the President of the Louisiana State Senate from 1924 to 1926, Gilbert succeeded to the lieutenant governorship on an interim basis until the expiration of the regular term in 1928.
Until he was sixteen years old, Gilbert attended the public and private schools of Assumption Parish.
On May 16, 1929, as the Senate President Pro Tempore, Gilbert, a loyal supporter of the new governor, Huey Pierce Long, Jr., was the first to sign the round robin to announce that the two-thirds state Senate majority could not be obtained for Long's conviction of the impeachment voted by the Louisiana House of Representatives.
"[2] In 1928, Gilbert became judge of the Louisiana 23rd Judicial District, a post that he held until his death.
He served as president of the Bank of Assumption which opened its doors for business in Napoleonville in 1901.