From Delta website:

Delta Pilot Basic Qualifications
To qualify for employment as a pilot at Delta you must have all of the following.

General Requirements

* At least 21 years of age
* Graduate of a four-year degree program from a college or university accredited by a recognized accrediting organization. Postgraduate education will be given favorable consideration
* Current passport or other travel documents enabling the bearer to freely exit and re-enter the U.S. (multiple reentry status) and be legally eligible to work in the U.S. (possess proper working documents)

FAA Requirements

* FAA commercial fixed-wing pilot license with an instrument rating
* Current FAA First Class Medical Certificate
* Passing score on FAA ATP written exam at time of interview

Flight Time Requirements

* Minimum of 1,200 hours of total documented flight time
* Minimum of 1,000 hours of fixed wing turboprop or turbofan time

When evaluating the flight time of applicants meeting the basic qualifications, consideration will be given to, among other things, quality, quantity, recency, and verifiability of training; complexity of aircraft flown; types of flight operations; hours flown as PIC; and recency and extent of flying experience. Applicants invited to interview must provide appropriate documentation of all flight hours.