Clarence's high school years represented a unique period at the school in that the Imperial Chinese Government had a program called the Chinese Educational Mission for sending young boys to Hartford Public and to Yale University for their higher education. Clarence maintained a lifelong friendship with these students, many of whom later rose to positions of prominence in the Chinese Republic. The student program was started in 1872 by Chinese reformer Yung Wing (Yale '54), the first Chinese person to graduate from a US university, who believed that China could become more competitive by learning Western methods. A total of 120 boys participated in the program (see boys leaving for America), but it was discontinued in 1881 by the Qing court on the grounds that students were losing touch with their Chinese heritage. Yung fled to the United States after the coup d'�tat of 1898 by the Empress Dowager CiXi, which resulted in many of his fellow reformers being beheaded and a $70,000 bounty being offered for his capture.

Clarence's career was closely tied to that of his father, Horace John Wickham, who was born in Glastonbury, Connecticut on April 1, 1836 and became one of the foremost citizens of Hartford during a time when it was the richest city in the nation. Horace was a descendant of Thomas Wickham, a Puritan settler who had emigrated from England to Wethersfield, Connecticut in about 1648. While many of Thomas' descendants, such as George Duncan Wickham, Charles Preston Wickham or Williams Carter Wickham, lived in areas far from Wethersfield, Horace was descended from Thomas' son William who stayed in Connecticut. For several generations, various Wickhams of this line lived on or adjacent to a large tract of land that had been held by the settler Thomas Wickham, which was part of the area set off from Wethersfield to become the town of Glastonbury in 1692. Their residences included the William Wickham House, built in 1685 by Horace's four-times great-grandfather (see house). Located on Main Street in Glastonbury, the house, unique for having dormer windows on adjacent sides, is a saltbox with later additions. Despite this venerable heritage, Horace was determined to make his mark in industry and left his father's farm at age seventeen with just "one dollar and fifty cents and a jack-knife."

After serving as a machinist apprentice in the clock industry in Bristol, Horace went to New Haven to work for the Whitney Gun Works during the time of the Civil War, then moved to Springfield, MA to serve as master machinist in the United States Arsenal. After the war, he took a position at the Plimpton Manufacturing Company in Hartford, where he developed an admirable reputation and fortune due to his many inventions that allowed the production of a machine which made stamped envelopes so cheaply that they were able to keep federal government contracts from 1874 to 1907. For thirty-three years all the stamped envelopes used by the United States government were made by the Wickham machines. Horace also developed a very cost effective machine for manufacturing newspaper wrappers. In 1881, he helped to organize the Hartford Manilla Company, which purchased the old powder mill property in Woodland. Of this company he afterwards became president. In 1894 he became a projector of the Hartford, Manchester and Rockville Tramway Company. Later he was for a time general manager of the company. It was through his interest and influence that Laurel Park was instituted, which became one of the most popular of the parks in the vicinity of Hartford.

As far back as his high school days, Clarence was connected with the Plimpton Manufacturing Company in Hartford, working under his father, and after graduation, continued with the company, and later became the Supervisor of the Stamped Envelope Division, during an association which lasted for 23 years. Clarence also became Secretary and Treasurer of the Hartford Manilla Company, which later became the Wickham Manufacturing Company. He was also for years Secretary and Treasurer of the Hartford, Manchester and Rockville Tramway Company. Clarence and Horace held over 40 original patents, the most famous being the one for the window envelope, which Clarence was credited with developing.

In 1896, on the first of many journeys to foreign lands, Clarence met Edith Farrell McGraft in Europe. She was the daughter of ex-mayor Newcomb Farrell McGraft of Muskegon, Michigan, and they were married in Muskegon on June 26, 1900. Edith, (see picture), was born in Saginaw, Michigan and the family name is perpetuated by McGraft Park and McGraft Memorial Congregational Church in that city. She attended Muskegon High School, the Conservatory of Music at Oberlin College, Ohio and the Ferris Business School, where she was the only woman in the class. Edith was a member of the South Congregational Church of Hartford and was very prominent in social, philanthropic and club activities. Clarence and Edith traveled extensively in the United States and abroad, visiting every continent at one time or another. They were particularly fond of the Far East and frequently visited Clarence's former high school classmates in China (see picture from 1920 trip). In the course of their travels they acquired many art objects, some of which are now located in the Oriental Garden in Wickham Park. In 1925-1926 Clarence made a continuous journey around the world, by way of New Zealand, Australia and South Africa. In the later part of 1931, the couple made a visit to Central Europe, ending in the Near East, and finding them in the Holy Land during the Yuletide Season. Edith died at the age of 88 years on June 6, 1960 and was buried near her husband in Cedar Hill Cemetery in Hartford, Connecticut (see grave).

Clarence was always interested in civic activities and patriotic organizations. From 1885 to 1887, Clarence served two terms in the Hartford Court of Common Council as Republican councilman from what was at that time the First Ward. He was a member of Company F, 1st Regiment, Connecticut National Guard from 1879 to 1892, being Captain during the last 2 1/2 years. He became a member of South Congregational Church in Hartford in 1901 and was Treasurer of the Alumni Association of the Hartford Public High School. In 1924, he was Major of the Veteran Battalion. He was president of the Col. Jeremiah Wardsworth Branch, Connecticut Society, Sons of the American Revolution, 1911-1913; president of the Connecticut Society, Sons of the American Revolution 1916 and 1918. He was Governor of the Connecticut Society of the Founders and Patriots of America for two terms, 1916 and 1918; and president of the Automobile Club of Hartford, 1917 and 1919. He served as president of the Republican Club of Hartford in 1925-1927, president of the Connecticut Society, Sons of the Revolution in 1928-1929. Besides these organizations in which Clarence held office, he was a member of the Society of Colonial Families, of the General Society of Colonial Wars, of the Sons and Daughters of the Pilgrims, of the Order of Indian Wars, and of the Connecticut Historical Society. He was also a Mason, (Knight Templar, 32nd Degree Mason, and a member of the Mystic Shrine). His club memberships included Rotary, Get Together, 20th Century, Hartford Club, Wampanoag Country Club, Sunset Ridge Country Club, Yorktown Country Club of Virginia, and the Midland Golf and Country Club, Midland, Ontario, Canada.

Both Clarence and Edith were generous donors and contributors to worthy causes during their lifetimes. They intended for many years to have their 130 acre estate in Manchester, known as The Pines, become a private park open to the public after their deaths and much of the development of their property was done with this objective in mind. Clarence left instructions with his trustee, Hartford National Bank (later Fleet National Bank), to continue this development after he and his wife died, leaving the bulk of his financial estate to establish a trust fund to finance its operation and maintenance. Clarence died on July 20, 1945 at the age of 85, and after Edith's death in 1960, the property, renamed Wickham Park, was opened to the public for the first time on July 1, 1961. The mansion on the property was intended to house the park superintendent, but was torn down in 1964 due to high maintenance costs, so the park's offices were moved to what was originally the Wickham's carriage house. A nearby log cabin, built in 1927 as a place to entertain family and friends, burned to the ground in 1989, but a replica was constructed on the original site. The Wickham estate of 130 acres was greatly supplemented by a gift from Myrtle Williams, who donated her adjacent 67 acre farm to the park in 1967. Through purchases and land swaps, the park reached its current 250 acres of gardens, woodlands, open fields, ponds, picnic areas, and sports facilities. Olmstead Associates of Brookline, Mass. were the designers for the original park layout and were also responsible for the redesign of the Oriental Garden. The park's theme of development has been based on the "enjoyment of nature" which is felt to have been the desire of the couple. Wickham Park remains private property, managed by Fleet National Bank, and no funds are received from tax sources. The couple also furnished a room in the Manchester Memorial Hospital and donated the Wickham Memorial Library, (see picture), in East Hartford in memory of Clarence's parents. Edith donated a community building in McGraft Park in Muskegon, and the residue of her estate was left in trust for the benefit of Wickham Park and the McGraft Memorial Congregational Church.