Today, he is one of the more than 200,000 African-Americans who have moved out of Chicago in the last two decades, though in some ways, he never left. For more than a year, he has taken this daily pilgrimage back to the house on Laporte, to the city where his children grew up and where two of his daughters still live.

The steady exodus of African-Americans has caused alarm and grief in Chicago, the nation’s third largest city, where black people have shaped the history, culture and political life. The population of 2.7 million is still nearly split in thirds among whites, blacks and Latinos, but the balance is shifting. Chicago saw its population decline in 2018, the fourth year in a row. Since 2015, almost 50,000 black residents have left.

They have been driven out of the city by segregation, gun violence, discriminatory policing, racial disparities in employment, the uneven quality of public schools and frustration at life in neighborhoods whose once-humming commercial districts have gone quiet, as well as more universal urban complaints like rising rents and taxes. At the same time, white, Latino and Asian residents are flowing in, and Chicago’s wealthier, whiter downtown, West Loop and North Side have been booming. Lori Lightfoot, the city’s first black mayor in decades, has vowed to stem the loss of longtime residents, and the city has collectively grasped for solutions.

The White family is a living symbol of what Chicago has kept and lost.

Members of three generations of the White family have grappled with the choice of whether to stay in Chicago or leave. Each family member’s story offers a glimpse into the city’s shifting migration pattern. Each story reveals what has made Chicagoans decide to leave the city or made them more determined to remain.

Mr. White, who arrived in Chicago from Mississippi when he was a teenager, moved to the suburbs because of the growing needs of his wife, Velma, who has dementia. Like many Chicagoans of his generation, he left the city only reluctantly.