Morrell was born in North Berwick, York County, Maine. He attended public schools and moved to Philadelphia, Pennsylvania in 1836, and entered a counting room as clerk. He later engaged in mercantile pursuits.
In 1855 he moved to Johnstown, Pennsylvania, and became general manager of the Cambria Iron Company, which was the greatest manufacturer of iron and steel in the United States until the Johnstown Flood. Morrell also served as president of the local gas and water company from 1860 to 1884 and as president of the First National Bank of Johnstown from 1863 to 1884. He was president of the city council for many years.
Morrell was elected as a Republican to the Fortieth and Forty-first Congresses. He served as chairman of the United States House Committee on Manufactures during the Fortieth and Forty-first Congresses. He was an unsuccessful candidate for reelection in 1870. He was a commissioner to the Paris Exposition of 1878.
Morrell became a member of and hounded the officials of the South Fork Fishing and Hunting Club, site of the infamous dam which formed Lake Conemaugh. The failure of that dam eventually caused the great Johnstown Flood of May 31, 1889. Morrell insisted on inspections of the dam's breastwork both by his own engineers and those of the Pennsylvania Railroad. He joined the club in order to keep a watchful eye on the matter. Unfortunately, his warnings went unheeded, and his offer to effect repairs partially at his own expense was rejected by club president Benjamin Franklin Ruff. Morrell died four years before the Johnstown Flood; his membership was then bought by Cyrus Elder, legal counsel for the Cambria Iron and Steel Company.
Morrell was again engaged in banking and died on August 20, 1885, in Johnstown, Cambria County, Pennsylvania.