• Passi was the pre-war capital of Iloilo Province in January 1942 to April 16, 1942 until the landing of Japanese Occupation Force.
• Passi was made the quartermaster depot of United States Army Forces in the Far East (USAFFE) for the food of the army that resisted in Bataan through Capiz.
• All her building in the central school became the seat of the provincial government offices including the Agricultural and Industrial Bank and the Philippine National Bank before the Japanese landing in Panay.
• Passi has the first warehouse of the Compania General de Tabacos de Filipinas in Central Panay which lately became the Roman Catholic Church and also the warehouse of the USAFE for foodstuff for Corregidor and Bataan.
• Ibajay Cave and mountain northeast of the poblacion was the seat of the Municipal Resistance Government under Mayor Filoteo Palmares and Municipal Treasurer Pedro Oro during the war years.
• Passi Central Elementary School (now Passi I Central School) had the first clean and beautiful ground^{[clarification needed]} in the province before the war.^{[citation needed]}
• One of the first regional high schools established in Iloilo was in Passi soon after liberation and one of the first to have acquired the widest site for high school of 12 hectares. Its athletic field cut from a hill and bulldozed by Mayor Palmares, leveled, and improved in time for the most lavished Unit Athletic Meet ever held in the interior in 1949–1959.
• The record of Passi in holding the First Provincial Athletic Meet in the interior before the war and in sustaining all the athletic delegations from different towns in Iloilo most abundantly and freely of which some meat uneaten were only given to them gratis et amore and some heads of cattle (surplus) sold for athletic fund ̶ still unbroken up to this day ̶ a feat that has never been or will ever be equaled in the history of athletic meets of Iloilo.
• In matters of bestowing the old Filipino traditional customs of being hospitable to individual visitor, visiting teams and districts, Passi’s record is yet unsurpassed because sumptuous foods and drinks offered by truckloads and caritos flow like water without reservation of any kind.
• Passi has the biggest cattle ranch in Panay before the war because of her wide grazing land.
• Passi therefore was the biggest supplier of meat for the army during the war and also the biggest supplier of rice and corn for sustenance of the guerilla forces and the Provincial Guards of the Civil Resistance Movement of Free Panay and Romblon Gov. Tomas Confesor.
• During Spanish regime, Passi was the home of wealthy families outside Iloilo City.
• Passi became the first component city of Iloilo in 1998.