Is there more to the question?
Andrew Johnson was the 17th president of the United States. Andrew became president in April 1865 after Abraham Lincoln was assassinated by John Wilkes Booth. Andrew Johnson helped keep the country together after the civil war which lasted from 1851 to 1865.
Andrew Johnson believed that that states had the right to make their own decisions about certain things like how they would treat freed slaves. He did not win the next election but he was elected to the U.S. Senate in the year of 1875.
The best way to combine these sentence into one correctly complete one is to use semicolon. In general, semicolon is used in order to combine two sentences that share similar idea into one. It is needed to avoid repetition and redundancy. So the correct sentence looks like this: These trains were not toys; they were detailed models built to try out ideas for real trains.
