Yes, that is exactly what you should tell them. 1  If two clauses are connected with a coordinating conjunction, it's a compound sentence. 2  If two clauses are connected with a subordinating conjunction, it's a complex sentence.
Trains were first- 1784, but cars weren't invented until 1890.
While John Quincy Adams was the first ex-president to ride a train in 1830, the first sitting president to travel by train was Andrew Jackson, when he rode the B & O from Ellicott's Mills to Baltimore in 1833. The first president-elect to ride a passenger train to an inauguration was William Henry Harrison, 8 years later. Harrison holds several other firsts. He was the first presidential candidate to campaign by train.