Answer by taking a quote from the following article:

Francis "Frank" Hague, born in Jersey City, was the fourth of eight children to John D. and Margaret Hague (nee Fagen), immigrants from County Cavan, Ireland. He was raised in Jersey City's Second ward, an area known as The Horseshoe due to its shape which wrapped around a railroad loop. The ward was created when the Republican-controlled legislature gerrymandered a district within Jersey City in 1871 to concentrate and isolate Democratic, and mostly Catholic, votes. By age 14, Hague was expelled from school prior to completing the sixth grade for poor attendance and unacceptable behavior.

In 1913, the first election for the city commission saw 91 men on the ballot competing for five available seats on the commission. Hague finished fourth with 17,390 votes and was elected to the first City Commission of Jersey City. The only Wittpenn-supported candidate, A. Harry Moore, was also elected. As a result of having garnered the most votes (21,419) former mayor Fagan became the first mayor under this new form of government, and the only Republican to hold that title in Jersey City for the following 75 years. Hague was named public safety commissioner, with control over the police and fire departments. In the same year, Hague cemented his control of the Hudson County political machine by securing for himself the leadership of the Hudson County Democratic Organization Executive Committee.  Hague immediately set about reshaping the corrupt Jersey City police force with tough Horsehoe recruits. Hague spearheaded crackdowns on prostitution and narcotics trafficking, earning him favor with religious leaders. These enforcement acts went as far as Hague himself marching across local Vaudeville stages personally directing the shut down of "girlie shows." At the heart of this change was an inner cadre of officers known as the Zeppelin Squad or "zepps" who were personally loyal to Hague alone. The "zepps" would spy on, and report back to Hague about other members of the department. Eventually, Jersey City had one patrolman for every 3,000 residents, causing a marked decline in the city's once-astronomical crime rate.  Hague took steps to curb the police department's lackadaisical work ethic, punishing offenses that had gone unpunished for years. He also made much-needed improvements to the fire department; at the time he took office Jersey City's fire insurance rates were among the highest in the nation.  Upon discovering in early 1916 that millions of pounds of munitions were being stockpiled on the Jersey City waterfront, Hague travelled to Washington, D.C. to register concerns for the safety of his constituents. His meetings with Congressmen resulted in no action, Congress having decided that Jersey City was an "appropriate port." Hague's concerns were shown to be valid in July 1916 when the Black Tom explosion sent shrapnel flying across the city.  In 1917, Hague, with his reputation as the man who cleaned up the police force, ran for reelection. He put together a commission ticket called "The Unbossed." The ticket consisted of him, Parks Commissioner Moore, Revenue Commissioner George Brensinger, ex-judge Charles F.X. O'Brien and City Clerk Michael I. Fagan. It swept all five spots on the commission. Moore topped the poll, and traditional practice called for him to be appointed mayor. However, when the commission met for the first time on May 11, Hague was chosen as the new mayor.

Where did Hague become a commissioner?
Hague finished fourth with 17,390 votes and was elected to the first City Commission of Jersey City.