O'Connell graduated from the College of the Holy Cross in 1910 and went to work for the bond department of Lee, Higginson & Co.
On December 31, 1935, O'Connell left Shawmut to become a resident partner of Soucy, Swartswelter & Co.[1][2] In addition to working for Soucy, Swartswelter & Co, O'Connell also served a president of Pilot Publishing Company and in 1939 was elected to the board of directors of the John Hancock Mutual Life Insurance Company.
[4] O'Connell and Irish-born trainer Thomas J. Barry purchased a number of race horses from Ireland during the late 1950s.
The pair purchased Cavan from Irish racehorse trainer Paddy Prendergast for an undisclosed sum.
In the 1958 Belmont Stakes, Cavan upset 3-20 favorite Tim Tam to prevent the horse from winning the Triple Crown.