The Eastland disaster brings the Red Cross to people's aid for the first time.

On the morning of July 24, 1915, more than 2,500 Western Electric employees and their families boarded the lake passenger steamer Eastland for a Michigan City outing. Almost immediately, however, the steamer tipped over and sank, leading to a loss of 844 lives – and making it the city’s worst disaster at the time. Organized just six weeks before the accident, the American Red Cross of Greater Chicago and its volunteers were on the scene within an hour of the tragedy.

The Chicago Region faces its first war relief operation when America enters World War I.

In that same year, the first local, public courses are taught by the Red Cross to educate Chicago citizens in first aid, hygiene and care for the sick.

A young Ernest Hemingway from Oak Park, Illinois joins the Red Cross at age 18 as an ambulance driver on the Italian front during World War I; an experience that would later serve as the inspiration for one of his best-loved novels, A Farewell to Arms.

Chicago faces epidemic crises from tuberculosis to smallpox, but one of deadliest is the “Spanish Flu” outbreak that claims the lives of nearly 2,500 victims in the City, 381 of them in just one day. Red Cross recruits 15,000 female nurses and aides who passed the Red Cross Home Hygiene course while another women-driven program, the Red Cross Motor Corps, transports nurses, doctors and patients and supplies to and from the City’s influenza wards.

The first local water safety programs are held on Chicago beaches.

Red Cross launches the first local, large-scale relief effort by distributing more than 120,000 sacks of flour to hungry Chicago families during the Great Depression.

Red Cross volunteers march in A Century of Progress Exposition parade to open the world’s fair held in Chicago.

Red Cross launches a large-scale response effort to one of Chicago’s most tragic fires at Our Lady of the Angels on the City’s Near West Side where the inferno claims the lives of 92 students and three nuns at the Catholic elementary school. Volunteers provide nursing care for the burn victims at St. Anne’s Hospital and package 1,200 gift boxes for the young survivors.

January 16 - Red Cross provides food and water for firefighters battling a five-alarm fire that destroys McCormick Place, Chicago’s largest exhibition and convention center.

April 21 - The Chicago region suffers its worst tornado outbreak when 10 twisters rake through northern Illinois, devastating the Oak Lawn community and taking 58 lives and injuring 1,000 more. Red Cross provides food and shelter to those left homeless by the disaster.

Red Cross prepares for the tumultuous Democratic National Convention in Chicago by supplying cots, blankets and first aid supplies for both authorities and human rights groups.

At the height of the Vietnam War, the Red Cross staffs 3,000 workers and volunteers at military hospitals and operates 67 field stations in Southeast Asia to facilitate communications between service members and their families, provide counseling and organize recreation programs for the troops. The Chicago Chapter sends 350 volunteers to help at hospitals and field stations.

Red Cross begins four-month Operation New Life for Vietnam refugees brought to the United States.

Red Cross aids Joliet, Crest Hill and Plainfield area residents after a tornado causes 29 deaths and 350 injuries.

Red Cross finds shelter for thousands of displaced residents when more than 124 million gallons of water from the Chicago River flood basements and underground facilities in the downtown Loop by a punctured century-old freight tunnel.

Red Cross volunteers go door-to-door to perform wellness checks during a deadly heat wave that hits the greater Chicago region during five consecutive days of temperatures reaching 99 °F and higher. At the height of the heat wave temperatures soar to a record setting 106 °F and the extreme humidity is blamed for more than 550 deaths in Cook County.

The Chicago area raises $29 million to help the Red Cross reconnect refugees from Kosovo, Bosnia with their families.

The Chicago Chapter develops a local fire prevention program that teaches families how to prevent home fires, create a disaster plan and check for fire hazards in their home.

Red Cross responds to terrorist attacks in New York, at the Pentagon and outside the town of Shanksville in rural Pennsylvania. Eighty-five Chicago-area volunteers are deployed to New York to help with the relief effort while local volunteer corps serve 50,000 meals to stranded passengers and offer counseling to distressed staff members at O’Hare and Midway airports.

The Chicago Chapter creates the Ready When the Time Comes program, a workplace volunteer initiative that trains employees of local businesses to be mobilized as Red Cross volunteers when a disaster strikes.

The Chicago Chapter activates the Patient Connection line that unites disaster victims with friends and relatives through a special hotline and call center set up during emergencies if a large number of people are hospitalized during a local incident.

April - The Rauner Center opens in the Illinois Medical District to serve as the Red Cross command facility and headquarters for the Chicago region. The generosity of donors, including Bruce and Diana Rauner and the State of Illinois, help bring this beautiful new facility from dream to reality.

April 20 - Eight fatalities are caused by a tornado that hits the Utica suburb while more injuries and destruction hit Joliet. Red Cross volunteers set up shelters for families whose homes were destroyed.

August –September - Hurricane Katrina becomes one of the most destructive storms in the history of the Gulf Coast, killing nearly 2,000 and leaving millions homeless. Red Cross mobilizes a massive national disaster relief effort. The Chicago Chapter partners with local organizations to coordinate relief effort to welcome more than 7,000 evacuees from the disaster zone.

December 31 - Ready When the Time Comes corporate volunteer program, with support from National Founding Sponsor W.W. Grainger, Inc., expands as a national program and is implemented in cities across the United States.

A magnitude 7.0 earthquake hits Haiti, leaving 1.5 million people homeless and prompting one of the largest single-country responses in the history of the global Red Cross and Red Crescent network. The public generously donates in support of the relief efforts, including donating via text messages on mobile phones, leading to a groundbreaking $32 million raised via SMS. Chicago area volunteers welcome Haitian repatriation flights and deploy to USNS Comfort and assist evacuees with their immediate needs.

Red Cross activates the Patient Connection program to reunite families with hundreds of Chicago Marathon runners hospitalized due to excessive heat.

“Snowmageddon” hits the city, one of the largest blizzards in Chicago history. The Red Cross opens warming shelters across the city to assist those stranded on Lake Shore Drive and across the city.

Superstorm Sandy makes landfall on the East Coast causing mass destruction to an area the size of Europe. More than 80 local Chicago area volunteers and staff join thousands of Red Cross workers in New York, New Jersey and other East Coast states to aid relief efforts and set up shelters for families displaced by the storm.

Red Cross is equipped to travel to blood drives across the Greater Chicago Region with the new mobile donation center.

April - Red Cross responds to major flooding in communities across the Chicago region by opening multiple shelters and a massive bulk distribution relief effort to hand out clean up kits to.

May - The Jay & Lori Bergman Blood Services Facility opens in The Rauner Center, increasing blood storage capacity and improving the ability of the Red Cross to provide rare and antigen-specific blood matches to critically-ill patients.

November 17 - A tornado tears through Central and parts of Northern Illinois. The Red Cross responds and aids in the recovery effort for families affected.

Red Cross responds to a spike in home fires due to extreme cold temperatures in the winter and launches a home fire preparedness effort to reduce the number of injuries and deaths by as much as 25% over the next five years.

January 21, 2015 - The Red Cross kicks off 100 years of serving Chicago with one of the largest single-day blood drives in the nation at Union Station where 430 units of lifesaving blood is collected.

February 25 - Large box truck is donated by Navistar to aid Red Cross in large-scale distribution efforts, including the ability to transport enough supplies to stand up a 200-person shelter.

The Chicago skyline lights up red in observance of the centennial celebration during March is Red Cross Month.