Final answer:
The sentence 'To his attentive audience he drew a loud elaborate plan of a very brilliant campaign' is a declarative sentence, as it provides information and ends with a period.
Step-by-step explanation:
The sentence in question is "To his attentive audience he drew a loud elaborate plan of a very brilliant campaign." This is a declarative sentence, because it makes a statement and provides information about what he did. A declarative sentence typically ends with a period, as does the sentence provided. This sentence is neither a command (imperative), a question (interrogative), nor an expression of strong emotion (exclamatory).