Final answer:
The most compelling claim for the historical significance of the marine chronometer is that it provided a reliable means to measure time and position at sea, revolutionizing 18th-century navigation and global affairs until the early 20th century.
Step-by-step explanation:
The best claim for an argumentative paragraph discussing why the marine chronometer is the most historically important object is that the chronometer is the most historically significant because it established a standard measure of time and position. This invention by John Harrison was pivotal in solving the 'problem of longitude,' which was critical for naval navigation and had a profound impact on exploration and trade. The maritime chronometer enabled sailors to determine their longitude at sea, a longstanding challenge that once solved, revolutionized maritime navigation in the 18th century.
Harrison's pursuit to create a clock that would maintain accurate time in the harsh conditions of sea travel was driven by the Longitude Prize, culminating in the success of his H4 chronometer. Even though he did not receive the full prize amount, his chronometers were instrumental in the development of precise naval navigation before the advent of radio signals in the early 20th century.
The maritime chronometer's role in navigation remained unchallenged until the early 20th century, when radio signals began to allow for the resetting of clocks on ships. Until then, the accurate keeping of time was essential for navigating the seas safely. The reliability of timekeeping devices such as the chronometer thus had a tremendous impact on the management of global affairs from exploration to military strategy.