Van der Hoff visited Potchefstroom and
Marico regularly, and established congregations at Suikerbosrand, Onder-Vaalrivier (roughly the present
Wolmaransstad,
Bloemhof,
Makwassie and
Christiana),
Pretoria, Draakberg (in the vicinity of the present
Volksrust and
Wakkerstroom),
Klerksdorp, Losberg and
Rustenburg. This meant that he was almost continually on the move, mostly by ox-waggon, in often inhospitable parts of the Southern Africa. On his journeys he twice fractured an arm and once fractured a leg, and for a time had to hold services while seated. Van der Hoff's advice was sought on nearly every aspect of the then unregulated society. In 1853 the Volksraad had adopted the 'Van der Hoff rules of procedure' for education, in terms of which the church was to continue to supervise education. After the adoption of the Transvaal constitution (1857) in which education was entrusted to the state, Van der Hoff was chair-man of the Board of Education until 1867. On the political level he also contributed towards stability. For instance, he tendered his resignation in protest in 1855, when the Volksraad rejected a draft constitution, but withdrew it when the constitutional bill was adopted in principle. With the adoption of the constitution in January 1857, the
Vierkleur, designed by Van der Hoff and his brother, was also adopted as the flag of the
Transvaal Republic. At Potchefstroom, Rustenburg and Pretoria Van der Hoff organized the religious part of the ceremonies marking the hoisting of the flag. For the occasion he also wrote a "Vlaggelied" which can be considered an early national anthem. The adoption of the constitution of 1857 meant that the Nederduitsch Hervormde Kerk became the state church. However, Van der Hoff refused to submit to state control. He also brought about order in the Church, although a first church law, drafted by him in 1857, was not accepted by the Volksraad. When, in 1861, A. J. Begemann became the minister at Pretoria, G. W. Smits went to Rustenburg, and, in 1864, N. J. van Warmelo arrived at
Soutpansberg, the scope of Van der Hoff's work was reduced. However, with the Church disputes caused by the Rev. F. Lion Cachet in 1865 and later, he found himself once again in the arena. He was also involved in a public dispute with the Rev. J. L. Jooste, the N.G. Kerk minister at Potchefstroom, from December 1868. ==Late career==