Parts of this area had already been developed for sugar cane plantations when the parish was organized, and that industry depended on numerous African American laborers who were freedmen after the war.

Mostly white yeomen farmers occupied areas in the piney woods and resisted planters' attempts at political dominance.

African Americans comprised about one-quarter of the population overall in the Florida Parishes before the war but were prevalent in the plantation areas, where they had been enslaved laborers.

Both physical and political conflicts arose in Tangipahoa Parish among interests related to construction of railroads, exploitation of timber, yeoman farmers in the piney woods keeping truck farms, and the beginning of manufacturing.

Through the turn of the twentieth century, the eastern Florida Parishes had the most white mob violence and highest rate of lynchings (primarily of black men) in southern Louisiana.

Piney woods whites resisted the planters' efforts to restore their political power, but imposed their own brutal violence on freedmen.

Tangipahoa Parish became more socially volatile by a "pronounced in-migration" of northerners (from the Midwest) and Sicilian immigrants, coupled with "industrial development along the Illinois Central Railroad, and crippling political factionalism.

Unlike some other parishes, Tangipahoa did not have a high rate of legal executions of blacks; the whites operated outside the justice system altogether.

They effectively excluded blacks from politics for decades, until after passage and enforcement of federal civil rights legislation.

In the first half of the 20th century, many African Americans left Tangipahoa Parish to escape the racial violence and oppression of Jim Crow, moving to industrial cities in the Great Migration.

Especially during and after World War II, they moved to the West Coast, where the buildup of the defense industry opened up new jobs.

In 2016, Tangipahoa was one of many parishes declared a Federal disaster area due to historic flooding from rainfall and storms in both March and August.

Keith Bardwell, justice of the peace for the parish's 8th ward (Robert, Louisiana), attracted attention in October 2009 for refusing to officiate the wedding of an interracial couple.

"[18] Bardwell said he had refused to perform the weddings of four couples during the 2½-year period before the news of his actions was publicized, resigned effective November 3, 2009.

Tangipahoa Parish is governed by an elected ten-member Council, each representing a geographic district and roughly equal populations.

In April 2016, the Parish hired its first chief administrative officer, Shelby "Joe" Thomas, Jr. to handle operating functions.

[23] The Sheriff's office was excluded from a DEA task force in 2016 after the Justice Department charged two deputies with stealing money and drugs seized in raids.