Fletcher began his law practice in Urbana, Ohio, and was the first attorney practicing law in Indianapolis. He was a prosecuting attorney for the Marion County Circuit Court in 1822 and 1823 and a prosecuting attorney for the Fifth Circuit Court in 1825 and 1826. Fletcher went on to join a law firm with Ovid Butler, Simon Yandes, and Horatio C. Newcomb. On December 26, 1846, Fletcher and Butler dissolved their law practice and collection business, but Fletcher continued to devote time to his farming operations and banking interests.
In 1825 he was elected state senator and remained in office until his resignation in 1833. This was the only political office Fletcher ever held. Fletcher was a member of the state Sinking Fund Commission from 1834 to 1841. He was affiliated with the anti-Jackson and Whig parties. As a member of the Free Soil party, Fletcher was a member of the party’s state committee and served as its convention chairman in 1849. In the 1850s Fletcher was a member of the Fusion party1 and then became active in promoting the Republican Party ticket in the 1856 state and national elections. In 1860 Fletcher supported the Republicans in state elections and Abraham Lincoln’s presidential election.
In 1844 Fletcher helped organize the State Bank of Indiana, where he acted as the Indianapolis branch's director from 1841 to 1844 and as branch president from 1843 to 1858. He remained active in banking for the rest of his life. In 1857 Fletcher was an organizer of the Indianapolis Branch Banking Company. In 1863 he joined his son, Stoughton, his brother, Stoughton, and fellow bankers Thomas H. Sharpe and Francis M. Churchman in organizing the Indianapolis National Bank, which was the second national bank in Indianapolis.
Fletcher was a stockholder in the Indianapolis and Bellefontaine Railroad (later called the Indianapolis, Pittsburgh and Cleveland Railroad) as well as a board member, and served briefly as its board president in 1855. Shortly before his death, Fletcher made a public appearance in support of a proposed Indianapolis-Vincennes railroad.
From 1839 to 1855 Calvin Fletcher owned a 269-acre farm called Wood Lawn in the early settlement of what would become known as Fletcher Place. After Fletcher sold his part of the farm at Wood Lawn, his son, Stoughton, divided it into lots and developed into a residential area. The settlement had several residents who made many contributions were made to the early development of architecture, religion, commerce, education, and social life in the city of early Indianapolis. By 1852 Fletcher’s farms adjacent to Indianapolis’s northeast side increased to approximately 1,400-acre. He also owned other farms in Marion County and in Morgan County, Indiana.
Fletcher was active in community service. Although Fletcher’s own education was limited, he was a strong supporter of a free public school system. In 1851 Fletcher was appointed to the Southeast District as one of three superintendents for the new Indianapolis free public schools. In 1853 the Indianapolis City Council appointed Fletcher as one of the first members of the Indianapolis Board of School Trustees. Fletcher was also appointed a trustee during the organization of Asbury College which became DePauw University, serving on the college’s board from 1837 to 1839 and as its treasurer from 1848 to 1855. Fletcher was also a trustee for the Marion County Seminary and the Indiana Female College.
Fletcher supported agricultural development and helped organize Indiana’s first agricultural fairs in the county and state. In addition, Fletcher was a founder of the State Horticultural Society. He also helped to found the Marion County Agricultural Society and was elected its president in 1851.
Fletcher was an abolitionist like his friend and colleague, Ovid Butler. In 1852 Fletcher’s long-standing interest in colonization led him to support a State Board of Colonization that would provide state funds to assist blacks living in Indiana to establish a colony in Africa. In addition, Fletcher and his family contributed to and participated in the American Civil War. Three of Fletcher’s sons served in the Union army. He also supported the organization of the U.S. colored troops in Indiana during the war and the 28th Regiment U.S. Colored Troops used his farm land to train between December 1863 and April 1864. During the war, Fletcher helped provide aid for soldiers’ families, assisted local efforts to welcome returning soldiers home, and served on the city’s Sanitation Committee. At the request of Indiana governor Oliver P. Morton, Fletcher purchased arms for Indiana’s regiments. After the war, Fletcher contributed to the Freedman’s Aid Society.
Fletcher assisted the Indianapolis Benevolent Society, a local organization that helped the city’s poor, serving for years as its secretary. He was also interested in the efforts of the Widows and Orphans Society and active in the temperance movement.
Fletcher was known as a very religious man. He joined the Methodist Church in 1829 and provided financial support to assist other denominations build their own churches. Fletcher served as superintendent of Sunday Schools at Asbury Chapel and Roberts Chapel, helped establish these Methodist congregations in Indianapolis, and also attended Wesley Chapel on the Circle. He contributed to the erection of almost all the early churches in Indianapolis. The Fletcher Place United Methodist Church was built on the on a portion of the farm, after the land had been donated to the church. Fletcher helped acquire property to establish Crown Hill Cemetery, a new burial ground at Indianapolis, and organized the nonprofit corporation to operate it.
Fletcher had a longtime interest in history. He was a member of the New England Historical and Genealogical Society and one of the original members of the Indiana Historical Society, founded in 1830. Fletcher's diary, donated to the IHS by his family in the 1920s, is in the IHS collections and provides “a powerful contribution” to understanding life in “the early nineteenth-century Midwest.
Fletcher died on May 26, 1866, after a brief illness and complications from injuries he suffered when he was thrown from his horse two months earlier. Fletcher was buried at Crown Hill Cemetery in Indianapolis. Keziah Fletcher sold the Fletcher home on Pennsylvania Street after her husband’s death, left Indianapolis, and returned to the East Coast, where she died in Boston on June 10, 1899. Several of the Fletcher children went on to have successful careers of their own.
A marble bust of Calvin Fletcher is on display in the Indiana Statehouse.