Allport played Pete Campbell's father, Andrew, on the 2007–15 drama series Mad Men during season one. Following Allport's death, the Writers of Mad Men had to kill his character, doing so in 'Flight One', where Andrew Campbell is one of those killed in the crash of American Airlines FLIGHT 1 in Jamaica Bay, New York, following take-off on March 1, 1962. The episode is dedicated in Allport's memory.
One of his earliest television roles was as Tim McGowan on the soap opera Another World (1973–74). Around 1975 or 1976, Allport did a screen test with Actress Amy Irving for the part of Han Solo and Princess Leia respectively for the upcoming filming of the 1977 movie Star Wars. Neither actor got the parts, which went to Harrison Ford and Carrie Fisher, respectively.
Allport had written a story about the pleasures of backcountry skiing in the Los Angeles Times in 2004 in which he stated that "any excursion into the mountains requires awareness. Have fun, but be careful."
Alexander Wise Allport Jr. was born in Boston. His acting life began at the age of nine in New Canaan, Connecticut, at the Children's Theatre. While at Northwestern University, he worked with Paul Sills and Story Theatre. He performed in New York with the Public Theater at Lincoln Center, and with Ensemble Studio Theatre; and in Los Angeles at the Taper, South Coast Repertory and with Padua Playwrights. In 2007, he wrote and starred in "The Backroad Home", a theatrical memoir with his original music, directed and developed by Paul Linke (Ruskin Theatre).
On January 25, 2008, Allport was one of three people killed by three avalanches near the Mountain High ski resort in Wrightwood, San Bernardino County, California (in the San Gabriel Mountains). There were two other fatalities: Michael McKay, an off-duty member of the resort's ski patrol, and Darin Bodie Coffey. A fourth man, Snowboarder Oscar Gonzales, escaped after getting lost and hitting a rock. Winter storms had been recently hitting Southern California; the San Gabriel Mountains, while usually free of avalanches, had been hit by 3 feet (0.91 m) of snow the week before Allport died.
